Anemias

Definition

Anemia is a blood disorder characterized by abnormally low levels of healthy red blood cells (RBCs) or reduced hemoglobin (Hgb), the iron-bearing protein in red blood cells that delivers oxygen to tissues throughout the body. Reduced blood cell volume (hematocrit) is also considered anemia. The reduction of any or all of the three blood parameters reduces the oxygen-carrying capability of the blood, causing reduced oxygenation of body tissues, a condition called hypoxia.

Description

All tissues in the human body need a regular supply of oxygen to stay healthy and perform their functions. RBCs contain Hgb, a protein pigment that allows the cells to carry oxygen (oxygenate) tissues throughout the body. RBCs live about 120 days and are normally replaced in an orderly way by the bone marrow, spleen, and liver. As RBCs break down, they release Hgb into the blood stream, which is normally filtered out by the kidneys and excreted. The iron released from the RBCs is returned to the bone marrow to help create new cells. Anemia develops when either blood loss, a slow-down in the production of new RBCs (erythropoiesis), or an increase in red cell destruction (hemolysis) causes significant reductions in RBCs, Hgb, iron levels, and the essential delivery of oxygen to body tissues.

Anemia can be mild, moderate, or severe enough to lead to life-threatening complications. More than 400 different types of anemia have been identified. Many of them are rare. Most are caused by ongoing or sudden blood loss. Other causes include vitamin and mineral deficiencies, inherited conditions, and certain diseases that affect red cell production or destruction.

Anemia in newborn infants is noted when hemoglobin levels are lower than expected for the birth weight and postnatal age. Premature or low birth-weight infants may have lower hemoglobin levels. The normal newborn Hgb is 16.8 dL, which may be 1 to 2 dL lower if birth weight is abnormally low. Anemia may be the first sign of certain disorders in the newborn, such as blood loss that has occurred from transplacental hemorrhage, a condition in which the infant's blood bleeds back into the mother's circulation; bleeding from ruptures in the liver, spleen, adrenals, or kidneys; or hemorrhage within the brain (intracranial hemorrhage). Anemia can also be caused by the destruction of red blood cells or reduced red blood cell production. Newborns may also have low red blood cell volume (hematocrit or Hct) if they were born by cesarean section . It must be noted, however, that hemoglobin decreases naturally (physiologic decrease) in infants by eight to 12 weeks of age, leveling at a normal value of 11 g/dL or better.

Iron-deficiency anemia

Iron deficiency anemia is the most common form of anemia worldwide. In the United States, it affects thousands of toddlers between one and two years of age and more than 3 million women of childbearing age. This condition is less common in older children and in adults over 50 and rarely occurs in teenage boys and young men.

The onset of iron deficiency anemia is gradual and may not have early symptoms. The deficiency begins when the body loses more iron than it derives from food and other sources. Because depleted iron stores cannot meet the red blood cell's needs, fewer red blood cells develop. In this early stage of anemia, the red blood cells look normal, but they are reduced in number. Then the body tries to compensate for the iron deficiency by producing more red blood cells, which are characteristically small in size (spherocytosis). Symptoms of anemia, especially weakness and fatigue, develop at this stage. Individuals may be given iron preparations by injection or advised to take oral iron supplements. It sometimes helps to take vitamin C along with oral iron supplementation to encourage better absorption of the iron. Taking iron supplements can result in diarrhea , cramps, or vomiting .

Folic acid deficiency anemia

Folic acid deficiency anemia is the most common type of megaloblastic anemia, arising from a problem with the synthesis of deoxyribonucleic acid (DNA) within the cells of the body. It is characterized by RBCs that are larger than normal and is caused by a deficiency of folic acid, a vitamin that the body needs to produce normal cells and normal DNA.

Folic acid anemia is especially common in infants and teenagers. This condition usually results from a dietary deficiency but may also be due to an inability to absorb (malabsorption) folic acid. Folic acid is available in many foods, such as cheese, eggs, fish, green vegetables, meat, milk, mushrooms, and yeast. Smoking raises the risk of developing this condition by interfering with the absorption of vitamin C, which the body needs to absorb folic acid. Folic acid anemia can be a complication of pregnancy, when a woman's body needs eight times more folic acid than it does otherwise. Folic acid deficiency in pregnant women may lead to birth defects in their children. Supplementation of folic acid is recommended during pregnancy.

Vitamin B₁₂ deficiency anemia

Less common in the United States than folic acid anemia, vitamin B₁₂ deficiency anemia is another type of megaloblastic anemia that develops when the body does not absorb enough of this nutrient. Necessary for the creation of healthy RBCs, B₁₂ is found in meat, eggs, whole grains, and most vegetables. Large amounts of B₁₂ are stored in the body, so this condition may not become apparent until up to four years after B₁₂ absorption stops or slows down. The resulting drop in RBC production can cause loss of muscle control; loss of sensation in the legs, hands, and feet; soreness, slickness, or burning of the tongue; weight loss; or yellow-blue color blindness . Confusion, depression, and memory loss may also be associated with the deficiency.

Pernicious anemia is the most common form of B₁₂ deficiency. Since most people who eat meat or eggs get enough B₁₂ in their diets, a deficiency of this vitamin usually means that the body is not absorbing it properly. This condition can be found in those who do not produce adequate amounts of a chemical secreted by the stomach lining that combines with B₁₂ to help its absorption in the small intestine. Pernicious anemia is diagnosed more often in adults between ages 50 and 60 than in children or young people, although there is the possibility of inheriting the condition, with symptoms not appearing until later in life.

Vitamin C deficiency anemia

Anemia due to vitamin C deficiency is a rare disorder that causes the bone marrow to manufacture abnormally small red blood cells. Vitamin C deficiency anemia results from a severe, long-standing dietary deficiency or malabsorption of this essential vitamin. It is usually easily corrected with supplementation.

Hemolytic anemia

Hemolytic anemia can be present at birth (congenital hemolytic anemia or spherocytosis) or acquired later in life. It is the result of either infection or the presence of antibodies that destroy RBCs more rapidly than bone marrow can replace them. Hemolytic anemia can enlarge the spleen, an organ that also produces red blood cells when necessary. Production of cells by the spleen will increase to meet the demands of accelerated RBC destruction (hemolysis). Complications of hemolytic anemia in older children or adults include pain , gallstones, and other serious health problems.

Hemolytic disease of the newborn is a specific variation of hemolytic anemia in which an incompatibility exists between antigens on the cells of the mother and baby, causing antibodies to develop in the mother's circulation. The antibodies are produced as an immune response to what the body views as foreign antigens on the surface of the infant's RBCs. Several specific antigens are responsible for the incompatibilities: Rh type incompatibility, ABO blood group incompatibility, and other incompatibilities involving antigens known as Kell, Duffy, M, N, and P, among many others. Hemolytic disease of the newborn and the anemia that results is detectable within the first few days after birth. Depending on the strength of the antibody, the anemia may clear up on its own or exchange transfusions may be necessary to replace the newborn's blood.

Thalassemia

An inherited form of hemolytic anemia, thalassemia comes from the production of abnormal hemoglobin. It is characterized by low hemoglobin and unusually small and fragile RBCs (microcytosis), although the RBC count may be normal. Thalassemia has several types that involve imbalances in the four chains of amino acids that comprise hemoglobin (alpha- and beta-globins). In thalassemia minor or thalassemia trait (heterozygous thalassemia), also called alpha-thalassemia, there is an imbalance in the production of the alpha chain of amino acids. In thalassemia minor, fetal hemoglobin (HbF), the hemoglobin form that circulates in the fetus, does not decrease normally after birth and may remain high in later life. A child may inherit thalassemia trait when only one parent has the genes responsible for it. It is usually not treated and does not have serious consequences. Thalassemia major (homozygous thalassemia or Cooley's anemia) occurs in children in whom both parents pass on the genes responsible. It is known as beta-thalassemia, because of an imbalance in the beta chain amino acids of hemoglobin. It also involves the persistence of HbF with larger than normal amounts appearing in the child's circulation. Alpha-thalassemias occur most commonly in African Americans; beta-thalassemias most commonly affect people of Mediterranean or middle-Eastern ancestry and Southeast Asians. Hemoglobin H disease is another form of thalassemia in which three of the four beta-globin genes are missing.

Sickle cell anemia

Sickle cell anemia is an inherited, chronic, incurable blood disorder that causes the body to produce defective hemoglobin, the abnormal HgbS, which occurs primarily in African Americans. The condition is characterized by abnormal, crescent-shaped RBCs. Unlike normal oval cells, fragile sickle cells cannot hold enough hemoglobin to nourish body tissues. The deformed shape makes it hard for sickle cells to pass through narrow blood vessels. When capillaries become obstructed, a life-threatening condition called sickle cell crisis is likely to occur. A child who inherits the sickle cell gene from each parent will have the disease. A child who inherits the sickle cell gene from only one parent carries the sickle cell trait but does not have the disease.

Aplastic anemia

Sometimes curable by bone marrow transplant, but potentially fatal, aplastic anemia is characterized by decreased production of red and white blood cells and platelets (disc-shaped cells that are a key component of blood coagulation). This disorder may be inherited or acquired as a result of the following:

• recent severe illness
• long-term exposure to industrial chemicals
• chemotherapy, use of anticancer drugs, and certain other medications

Anemia of chronic disease

Cancer , chronic infection or inflammation, and kidney and liver disease often cause mild or moderate anemia. Chronic liver failure generally produces the most severe symptoms because the production of RBCs is directly affected.

Causes and symptoms

Anemias do not all stem from the same causes. Anemia can be the result of injuries, chronic or acute illnesses, complications of surgery or childbirth , metabolic disturbances or deficiencies, and adverse response to drug therapy administered for other conditions. Causes may include sudden or ongoing loss of blood, nutritional deficiencies, decreased red blood cell production, or increased red blood cell destruction. Malnutrition or malabsorption of nutrients can contribute to vitamin deficiency anemia and iron deficiency anemias. Although red cell destruction and replacement is an ongoing process in the body, hereditary disorders and certain diseases can accelerate blood cell destruction, resulting in anemia. However, excessive bleeding is the most common cause of severe anemia, and the speed with which blood loss occurs has a significant effect on the severity of symptoms. Chronic blood loss may be a consequence of the following:

• cancer
• gastrointestinal tumors
• diverticulosis
• polyposis
• heavy or frequent menstrual flow
• hemorrhoids
• nosebleeds
• stomach ulcers
• long-standing alcohol abuse

Acute blood loss may occur as a result of injury, a ruptured blood vessel, or a complication of surgery or childbirth. When a lot of blood is lost within a short time, blood pressure and the amount of oxygen in the body drop suddenly, sometimes leading to heart failure or death. Loss of even one third of the body's blood volume in the space of several hours can be fatal. Gradual blood loss is less threatening, because the body has time to replace RBCs and blood volume.

Symptoms

Weakness, fatigue, and a run-down feeling may be the first signs of anemia. Pasty or sallow skin color, or the absence of color in the gums, nail beds, creases of the palm, or lining of the eyelids are other signs of anemia. Individuals who appear to be weak, easily tired, often out of breath, and who may feel faint or dizzy on movement may be severely anemic.

Other symptoms of anemia may include the following:

• unusual cravings for ice (chewing on ice cubes), paint, or earth (actually eating dirt)
• headache
• inability to concentrate, memory loss
• inflammation of the mouth (stomatitis ) or tongue (glossitis)
• insomnia
• irregular heartbeat
• loss of appetite
• dry, brittle, or ridged nails
• rapid breathing
• sores in the mouth, throat, or rectum
• perspiration, especially around the head and neck
• swelling of hands and feet
• constant thirst
• ringing in the ears (tinnitus)
• unexplained bleeding or bruising
• angina pectoris, i.e., chest pain accompanied by a choking sensation that may provoke anxiety

Demographics

Acquired anemias affect about 4 million individuals in the United States, and over 50 percent of these are under age 45, although less than 10 percent of cases occur in children and adolescents. In the United States, iron deficiency anemia is the most prevalent type of anemia, affecting about 240,000 toddlers between one and two years of age and 3.3 million women of childbearing age. Anemia due to gradual blood loss is more common in women than in men, particularly pregnant women or women of menstruating age. Pernicious anemia is more common in women and in African Americans and is less common in other racial groups. Folate deficiency is not common in young people who eat an adequate diet and is usually associated with malnutrition, pregnancy, and alcoholism . Sickle cell anemia is more frequently diagnosed than thalassemias and occurs most often among African Americans. Thalassemia occurs in four out of 100,000 individuals in the United States, particularly among those of Mediterranean, Asian, or middle Eastern descent.

When to call the doctor

When a child exhibits weakness, dizziness , listlessness, or fatigue, it may be the first sign of anemia. The pediatrician should be consulted if the child is also extremely pale or has little or no color in the gums, nail beds, creases of the palm, or lining of the eyelids. Any prolonged bleeding or sudden blood loss requires examination by a physician and testing for anemia.

Diagnosis

The child's medical history will be taken, including the child's age, symptoms, illnesses, and general state of health, and a family history of ancestry and known inherited anemias will be noted. Symptoms noticed in children by their parents may include fatigue, weight loss, inability to concentrate, loss of appetite, and light-headedness when standing up. The physical examination may reveal paleness, lack of color in the creases of the palm, gums, and the linings of the eyelids. The child's breathing rate may be increased and, in advanced cases, the spleen or liver may be enlarged when palpated. If anemia is due to chronic disease, there may be evidence of infection or inflammation. Urine output may be reduced in severe anemia.

Diagnostic testing begins with a complete blood count (CBC) and differential to reveal the RBC count, white blood cell (WBC) count, hemoglobin (Hgb), and hematocrit (Hct); any of these counts can be altered, and in most anemias the RBC and hemoglobin will be reduced. The mean corpuscular volume (MCV) will be measured to compare the size of RBCs with normal RBCs. A reticulocyte (young RBCs) count will help determine if anemia is caused by impaired RBC production or increased RBC destruction. Iron, vitamin C, vitamin B₁₂, and folate levels will be measured to evaluate and identify possible deficiencies. Diagnosing thalassemia and sickle cell anemia, both of which involve disorders of hemoglobin, will require measuring the different types of hemoglobin through a laboratory testing method called hemoglobin electrophoresis. In some anemias, a bone marrow sample will be removed (bone marrow biopsy) for microscopic examination, especially to confirm iron deficiency anemia or the megaloblastic anemias. Kidney function tests, coagulation tests, and stool examinations for occult blood may also be performed.

Treatment

Surgery may be necessary to correct blood losses caused by injury or hemorrhage (nose bleeds, aneurysm, cerebral hemorrhage, bleeding ulcer) or childbirth. Transfusions of packed red blood cells or whole blood may also be used to replace blood volume and to stimulate the body's own production of red blood cells. Medication or surgery may also be necessary to control heavy menstrual flow or to remove polyps (growths or nodules) from the bowels.

Anemia due to nutritional deficiencies can usually be treated with iron replacement therapy, specific vitamin supplements, or self-administered injections of vitamin B₁₂. People with folic acid anemia may be advised to take oral folic acid.

Vitamin B₁₂ deficiency anemia requires a life-long regimen of B₁₂ shots to maintain vitamin levels and control symptoms of pernicious anemia. The patient may be advised to limit physical activity until treatment restores strength and balance.

Anemia resulting from chronic disease is typically corrected by treating the underlying illness. This type of anemia rarely becomes severe. If it does, transfusions or hormone treatments to stimulate red blood cell production may be given.

Thalassemia minor is typically not treated. Thalassemia major may be treated with regular transfusions, surgical resection of the spleen to avoid its removal of RBCs from circulation, and sometimes iron chelation therapy. Symptoms are treated as they occur. Children or young adults with thalassemia major may require periodic hospitalization to receive blood transfusions or, in some cases, bone marrow transplants.

Sickle cell anemia will be monitored by regular eye examinations and diagnostic blood work. Immunizations for pneumonia and infectious diseases are part of treatment along with prompt treatment for sickle cell crises and infections of any kind. Psychotherapy or counseling may help older children deal with the emotional symptoms characteristic of this condition.

Children with aplastic anemia are especially susceptible to infection. Treatment for aplastic anemia may involve blood transfusions and bone marrow transplantation to replace malfunctioning cells with healthy ones.

Hemolytic anemia of the warm-antibody type may be treated with large doses of intravenous and oral corticocosteroids (cortisone). Individuals who do not respond to medical therapy, may undergo surgery to remove the spleen, which controls the anemia in some individuals by helping to add more RBCs to the circulation. Immune-system suppressants are prescribed when surgery is not successful. There is no specific treatment for cold-anti-body hemolytic anemia.

Treatment of newborn anemia depends on the severity of symptoms, the level of Hgb, and the presence of any other diseases that may affect oxygen delivery, such as lung or heart disease or hyaline membrane disease. Transfusions may be given in certain situations or exchange transfusions if hemolytic disease of the newborn is not quickly resolved. The risk of transfusion (such as transfusion reactions, potential toxins, and infections such as HIV or hepatitis) are carefully weighed against the severity of the anemia in the infant.

Alternative treatment

Vitamin C is noted for helping to absorb iron and folate supplements. Cooking in a cast iron skillet may leach small amounts of absorbable iron into the diet. Folic acid can be readily absorbed from raw salad greens such as lettuce, spinach, arugula, alfalfa sprouts, and others. Blackstrap molasses is a good source of iron and B vitamins . Herbal supplements that will benefit individuals who have anemia include bilberry, dandelion, goldenseal, mullein, nettle, Oregon grape root, red raspberry, and yellow dock. Herbs are available as tinctures and teas or in capsules.

Nutritional concerns

The diet is a ready source of nutrients that prevent and treat anemia. Children with anemia can include more of these nutrients in their diet by eating a broad variety of whole grains, fruits and vegetables, beans, lean meat, poultry and fish, and supplementing the diet regularly with vitamins, minerals , and iron (as recommended). Pediatricians should be consulted before iron supplements are taken, however, because of the difficulty in absorbing non-food sources of iron. Vitamin C can stimulate iron absorption. Good food sources of iron include: almonds, broccoli, dried beans, raisins, dried apricots, seaweed (as soup stock), whole-grain breads and cereals, brown rice, lean red meat, liver, potatoes, poultry, and shellfish.

Because light and heat destroy folic acid, fruits and vegetables should be eaten raw or cooked as little as possible to help assimilation of folic acid. Folic acid can also be taken as a supplement.

Prognosis

Most anemias can be treated or managed. The prognosis for anemias generally depends upon the severity of the anemia, the type of anemia, and the response to treatment. The hereditary anemias, such as the thalassemias and sickle cell anemia, may require life-long treatment and monitoring whereas other types of anemia, once treated, are apt not to recur. Thalassemia major may cause deformities and may shorten life expectancy. Severe anemia may lead to other serious conditions, particularly if oxygen delivery is compromised for long periods of time or RBC destruction is more rapid than can be controlled by normal RBC replacement or specific treatment. Severe blood loss or prolonged anemia can result in life-threatening complications.

Prevention

Safety is the primary preventive measure for blood loss by injury. A wholesome, balanced diet rich in nutrients can help prevent dietary deficiencies that lead to anemia. Hereditary anemias cannot be prevented; parents can seek genetic testing and counseling if they are concerned about inherited anemias noted in their families or ethnic background.

Nutritional concerns

Sources of iron such as liver, red meat, whole grains, and poultry may help maintain hemoglobin levels and reduce the likelihood of deficiency-related anemias. Vitamin C is noted for helping to improve assimilation of iron taken as supplements.

Parental concerns

Parents may be particularly concerned about the possibility of inherited anemias. Genetic testing is available to address their doubts. Nutrition education is readily available from public health sources, books, and the reliable Internet sources for parents who are concerned about providing essential nutrients for children who may be susceptible to deficiency anemias. Regular physical examinations can help evaluate a child's overall health and reveal possible signs or symptoms of anemia.

KEY TERMS

Erythropoiesis —The process through which new red blood cells are created; it begins in the bone marrow.

Hematocrit —A measure of the percentage of red blood cells in the total volume of blood in the human body.

Hemoglobin —An iron-containing pigment of red blood cells composed of four amino acid chains (alpha, beta, gamma, delta) that delivers oxygen from the lungs to the cells of the body and carries carbon dioxide from the cells to the lungs.

Hemolysis —The process of breaking down of red blood cells. As the cells are destroyed, hemoglobin, the component of red blood cells which carries the oxygen, is liberated.

Hypoxia —A condition characterized by insufficient oxygen in the cells of the body

Megaloblast —A large erythroblast (a red marrow cell that synthesizes hemoglobin).

Reticulocyte —An early, immature form of a red blood cell. Over time, the reticulocyte develops to become a mature, oxygen-carrying red blood cell.

Resources

BOOKS

"Blood Disorders." The Merck Manual of Medical Information, 2nd Home ed. Edited by Mark H. Beers et al. White House Station, NJ: Merck & Co., 2003.

Hill, Shirley, A. Managing Sickle Cell Disease in Low-Income Families. Philadelphia: Temple University Press, 2003.

Lande, Bruce. Aplastic Anemia and Other Autoimmune Diseases: Help Your Body Heal Itself. Syracuse, NY: Action Enterprises, 2003.

Ross, Allison J. Everything You Need to Know about Anemia. New York: Rosen Publishing Group, 2001.

Wick, M., et al. Iron Metabolism, Anemias, Clinical Aspects and Laboratory. New York: Springer, 2003.

ORGANIZATIONS

National Heart, Lung, and Blood Institute (NHLBI). 6701 Rockledge Drive, PO Box 30105, Bethesda, MD 20824–0105. Web site: <http://www.nhlbi.nih.gov>.

WEB SITES

"Anemia." KidsHealth. Available online at <http://kidshealth.org/parent/medical/heart/anemia.html> (accessed October 10, 2004).

"Understanding Anemia: Your Life May Depend on It." Anemia Lifeline. Available online at <www.anemia.com> (accessed October 10, 2004).

L. Lee Culvert Maureen Haggerty

Anemia

Carrie’s Story

What Is Anemia?

How Is Blood Made in a Healthy Person?

What Is Different in a Person with Anemia?

What Are the Different Types of Anemia?

First Category: Anemia from Blood Loss

Second Category: Decreased Production of Red Blood Cells

Third Category: Hemolytic Anemias

How Do People Know If They Are Anemic?

Doctors as Detectives: Diagnosing Anemia

Scientific Research

Resources

Anemia is a condition that occurs when there are too few properly functioning red bloods cells to carry enough oxygen to the body. Anemia may have different underlying causes. Treatment of anemia depends on its cause and may involve dietary changes, medication, and blood transfusions.

KEYWORDS

for searching the Internet and other reference sources

Erythrocytes

Hematology

Hemoglobin

Hemolysis

Carrie’s Story

When Carrie turned thirteen, she was determined to finally lose all of what she called her “baby fat.” She longed to look like the skinny models who graced the covers of the fashion magazines. Carrie stopped eating the well-balanced meals her mother made. Instead, she grabbed rice cakes or low-fat chips to stop the hunger pangs. At about the same time, Carrie got her period for the first time.

It was not long before Carrie started to feel lightheaded whenever she stood up, and in gym class she had to stop and rest every five minutes. Her gym teacher noticed Carrie’s behavior and how pale she looked and suspected that Carrie had iron deficiency anemia. This type of anemia is very common in teenage girls because of poor eating habits and iron loss due to menstruation.* At the coach’s suggestion, Carrie visited her doctor. Together Carrie and her doctor came up with a healthy diet and exercise plan to help Carrie reach an appropriate weight and keep her iron level normal.

* menstruation

(men-stroo-A-shun) is the discharge of bood and tissue through the vagina that occurs periodically to women of child-bearing age. Because it usually occurs at about four-week intervals, it is often called the “monthly period.”

What Is Anemia?

Anemia (a-NEE-me-a) is not a disease in itself. Instead, it is a sign that the body has a problem with its red blood cells. The blood of a person with anemia does not contain enough red blood cells or enough of the protein hemoglobin (he-mo-GLOW-bin). Anemia can develop because of poor nutrition, excessive blood loss, destruction of red blood cells, abnormal hemoglobin, or from a number of other causes. But no matter what causes anemia, the result is always the same: the blood does not carry enough oxygen to the cells throughout the body, so the body cannot function normally.

How Is Blood Made in a Healthy Person?

Blood consists of red blood cells, white blood cells, platelets, and plasma. Red blood cells, or erythrocytes (e-RITH-ro-sites), are the most numerous cells in the blood and give blood its red color. The tissues and cells in the body require oxygen to function properly, and erythrocytes are specialized to carry and distribute oxygen because they contain hemoglobin. Hemoglobin has the unique property of being able to absorb oxygen in the lungs, where it is plentiful, and release oxygen to the cells of the body, where it is needed. Hemoglobin consists of four protein molecules, called globins, and up to four heme molecules. The heme molecules are red-pigmented, nonprotein, iron-binding compounds, and they are responsible for binding to and transporting oxygen and carbon dioxide.

The U.S. and the World

UNICEF estimates that 2 billion of the world’s 6 billion people are iron deficient, which is one of the leading causes of anemia worldwide.

More than 50 percent of children under age 4 in developing nations are anemic, according to the World Health Organization.

An estimated 110,000 people worldwide died of anemia in 1998. About 95,000 of them lived in low- and middle-income nations.

In 1997, 4,471 people died of anemia in the United States. About 65 percent of them were 75 years or older.

A1995 estimate put the number of Americans with anemia at 4.1 million, including 2.5 million under age 45.

The death rate from anemia is about 42 percent higher for women than for men.

The death rate from anemia is almost 70 percent higher for people of African ancestry than for people of European ancestry.

In a healthy person, erythrocytes are produced by a process called hematopoiesis (he-ma-tow-po-EE-sis). Hematopoiesis takes place in the bone marrow, which is the tissue that fills the center of most bones. All blood cells originate from one type of cell in the marrow called a stem cell. As red blood cells are produced from stem cells and mature in the marrow, they begin to fill with hemoglobin. A healthy red blood cell contains about 300 hemoglobin molecules, and these take up most of its volume.

When erythrocytes mature, they also get rid of most of the normal components of cells (such as DNA, the nucleus, the endoplasmic reticulum, and the mitochondria). Without these components, erythrocytes cannot grow and divide, so they have a short life. Each cell survives for only about 120 days. The spleen, which is an oval organ located between the stomach and the diaphragm on the left side of the body, contains cells called macrophages (MAK-ro-fayj-ez). The macrophages engulf and break down the old, dying erythrocytes and recycle the iron from the hemoglobin molecules so that it can be used to make more hemoglobin. Every second, about 2 million erythrocytes die, and they must be replaced by hematopoiesis at exactly the same rate.

If the body detects a shortage of red blood cells, the kidneys make a hormone called erythropoietin (ee-rith-ro-po-EE-tin). This protein is secreted into the blood, which then signals the bone marrow to make more red blood cells.

Granny Heath and Liver Therapy

Before and during the early twentieth century, the ingestion of great amounts of liver served as an effective means for preventing and treating most types of anemia.

In My Second Life (1944), author and physician Thomas Hall Shastid recalls his school teacher “Granny Heath,” who advocated that, cooked or raw, the liver of just about any farm animal was the perfect remedy for what she called the “littleness of blood.”

Medical history records that Dr. George R. Minot (1885-1950), Dr. William Parry Murphy (b. 1892), and Dr. George Hoyt Whipple (1878-1976) were the actual creators of the first effective treatment for pernicious anemia using liver. They were awarded the Nobel Prize in 1934 for their research on blood chemistry and histology, which established the scientific basis for successful use of liver therapy.

What Is Different in a Person with Anemia?

Blood production is a complex process that requires communication between many parts of the body, including the bone marrow, the kidneys, and the spleen. There are many places in the process where something can go wrong. Problems with stem cells, replication and maturation of erythrocytes, the manufacture of hemoglobin, improper signaling between the kidney and bone marrow (erythropoietin), and problems with spleen function (destruction of cells by macrophages) can result in anemia. A person can have anemia because of an inherited blood disorder, because of a blood condition he or she acquired somehow, and even because of diseases not directly related to the blood.

There are several dozen types of anemia that are categorized by their underlying cause. When doctors test blood for anemia, they often describe the blood by the hemoglobin content of red blood cells (color) and by the size and shape of red blood cells. These descriptions can point a doctor toward the underlying disorder. Treatment is specific for each type of anemia and is based on treating the underlying disease.

What Are the Different Types of Anemia?

There are three broad categories of causes of anemia. First, when someone is injured and loses a great deal of blood, anemia can develop because the body’s total blood volume is lost faster than it can be replaced. In the second category, the process of making red blood cells in the body is not working normally: bone marrow does not make enough erythrocytes, the erythrocytes do not contain enough hemoglobin, or the hemoglobin does not function correctly. In the third category, red blood cells are destroyed faster than the marrow can replenish them. Some of the most common types of anemia in each category are described below.

First Category: Anemia from Blood Loss

People who lose a lot of blood very quickly, like those who have been injured in an accident, had a blood vessel burst, or have lost blood during surgery, can become anemic because the body cannot make blood as fast as it is being lost. In cases where blood loss is life threatening, a person can have the lost blood replaced through a blood transfusion*. In less severe cases, the body will slowly bring the blood volume and hemoglobin content back to normal by itself. In fact, a person can lose two-thirds of his or her blood volume over a 24-hour period without dying. Other people have a place in their body that is constantly bleeding a little bit, such as a wound in the skin or mucous membranes inside the body (ulcer). In these cases, the source of bleeding needs to be found and treated, and dietary supplements of iron often are needed to help boost hemoglobin production.

* blood transfusion

is the process of giving blood (or certain cells or chemicals found in the blood) to a person who needs it.

Second Category: Decreased Production of Red Blood Cells

Anemias caused by a decreased production of red blood cells are also called hypoplastic anemias, and many different conditions and disorders can cause this kind of anemia.

Nutritional causes

Certain important vitamins and minerals, such as iron, vitamin B12, and folic acid, are necessary for the bone marrow to make hemoglobin and erythrocytes. If these elements are missing from the diet or are not absorbed from the diet, anemia can develop. Adding food rich in these elements or adding supplements to the diet helps replenish the blood supply.

Iron deficiency anemia occurs when a person does not eat enough foods containing iron or when the body has problems absorbing iron. A low iron level in the body means that there is not enough iron available to make hemoglobin, which results in decreased production of red blood cells. This is a very common type of anemia, especially in infants and teenagers, who need lots of iron to fuel growing bodies. Also, 30-50% of American women are at risk for anemia because of blood loss during menstruation and inadequate amounts of iron in their diets to offset these monthly losses. Iron deficiency anemia is characterized by small red blood cells.

Pernicious anemia occurs when a person does not eat enough foods containing vitamin B12 or is unable to absorb B12 properly. To absorb vitamin B12, the lining of the stomach must produce hydrochloric acid and make a chemical that scientists call “intrinsic factor.” If acid production is decreased or intrinsic factor is missing, the vitamin cannot be absorbed. This type of anemia usually affects adults between the ages of 50 and 60, but it is rare in African American and Asian people. People with a poor diet, bulimia, anorexia nervosa, diabetes, or thyroid disease, or who have had stomach surgery, stomach cancer, or a family history of pernicious anemia are prone to this problem. It usually develops gradually, so the symptoms are hard to detect.

Genetic causes

Sometimes people are born with diseases that diminish the body’s ability to produce red blood cells. Thalassemia (thal-a-SEE-me-a) and sideroblastic (sid-er-o-BLAS-tik) anemia both occur because the bone marrow cannot produce hemoglobin normally.

Thalassemia is an inherited disorder in which the rate of hemoglobin production is too low. In this condition, the globin portion of hemoglobin is defective. This disorder is most common in people of Mediterranean, African, and Asian ancestry. Thalassemia is divided into two categories: major and minor. People born with thalassemia major have severe anemia during the first year of life that results in slow growth, abnormal bone development, and an enlarged liver and spleen. People with thalassemia minor often do not have any symptoms.

In sideroblastic anemia, the heme molecule of hemoglobin is not made correctly. This problem can be a genetic disorder, but it also can occur in people suffering from alcoholism, people exposed to toxins such as lead, or people who have acquired bone marrow disorders.

Aplastic anemia and bone marrow disorders

Aplastic anemia describes a category of anemias in which the hematopoietic (blood-forming) cells of the bone marrow are destroyed. In many cases, doctors do not know why these cells have been destroyed. In other cases, the blood-forming cells are destroyed by cancer of the bone marrow or by exposure to toxic chemicals, radiation, certain antibiotics, or other medications. A bone marrow transplant from an identical twin or from a relative with compatible cell types can be used to treat aplastic anemia, but it is often difficult to find a donor with the right cell type. Finding treatment for aplastic anemia is an active field of research.

Infection and other disorders

People who frequently are ill with infections are prone to anemia because the infection causes the production of red blood cells to slow down. Anemia is very common in people with AIDS because their immune systems* do not function normally and they are prone to infections. People who have diseases of their kidneys often develop anemia because the kidneys no longer respond to decreases in red blood cells by producing enough erythropoietin.

* immune system

fights germs and other foreign substances that enter the body.

Third Category: Hemolytic Anemias

Hemolytic anemias are caused by the premature destruction of red blood cells. Erythrocytes can be destroyed too quickly or too early because of infection, because the hemoglobin produced is abnormal, because the spleen does not function properly, or because a person has been exposed to certain drugs or toxic chemicals. Red blood cells can have defects in the membrane that surrounds them, which leads to their destruction by macrophages. Hemolytic anemia also can be caused by problems with the immune system.

Sickle cell anemia and genetic causes

Sickle cell anemia is the most well-known type of hemolytic anemia. It is a genetic disease, meaning that a person inherits the genes* for the condition from his or her parents. If the person received only one copy of the affected gene (from one parent), he or she is said to have the sickle cell trait. A person who received the gene from both parents will have sickle cell disease. This type of anemia occurs most frequently in people of African ancestry. In the United States, 0.3% of the African-American population (over 50,000 people) has this disorder. People with sickle cell disease frequently have severe anemia, episodes of pain, delayed growth, and increased infections. People with sickle cell trait usually have no symptoms of anemia and grow and develop normally.

* genes

are the material in the body that helps determine physical and mental characteristics, such as whether a person has brown hair or blue eyes.

In a person with sickle cell anemia, the hemoglobin is different from that in healthy erythrocytes and it causes the red blood cells to be shaped like crescents. Because of this shape, they cannot easily flow through the bloodstream and they are destroyed faster than the body can replace them.

Autoimmune diseases

People with autoimmune diseases, such as rheumatoid arthritis, can develop hemolytic anemia. In autoimmune diseases, the body’s immune system does not work correctly. In addition to destroying foreign cells, such as bacteria that cause infection, the abnormal immune system attacks and destroys its own cells, including erythrocytes. In some people, drugs that reduce the immune system’s activity (immunosuppressives) are used to treat anemia.

What Do Babies and Teenage Girls Have in Common?

Infants and teenage girls are at risk of developing iron-deficiency anemia. Teenage girls are at risk because they lose blood when they begin to menstruate and because they are undergoing growth spurts. These factors combined with an iron-poor diet (many teenage girls are concerned about their weight and how they look, so they go on diets that do not provide enough iron) often result in anemia.

Babies need lots of iron to fuel their rapid growth; their blood volume is expanding as quickly as the rest of their body is growing. Many doctors test 6- to 12-month-old babies for anemia, even if they seem to be happy and healthy, because historically, many babies developed iron-deficiency anemia between these ages. Today, only 2 to 3 percent of middle class infants develop anemia, and this is largely due to the iron added to baby formula and baby cereals. For breastfed babies, the iron in cereal or in supplements is especially important, because breast milk cannot provide enough iron. For older children and adults, adding a food with vitamin C, such as oranges, cantaloupe, or broccoli, helps the body to absorb the iron. Unfortunately, the rates of anemia are higher in poor communities because of poor nutrition.

How Do People Know If They Are Anemic?

People who have mild anemia often have no symptoms. For people with more severe anemia, how they feel depends on how old they are, how fast the anemia developed, and what other illnesses they might have. If the anemia develops rapidly, a person is more likely to be aware of symptoms. If it develops over a long period of time, even people with moderate anemia may have few obvious symptoms.

Like Carrie, people with moderate to severe anemia may feel tired, weak, dizzy, and short of breath, all because the cells of the body are not getting enough oxygen. This lack of oxygen can cause them to be irritable and lose interest in what is going on around them. Sometimes people with moderate to severe anemia look pale and waxy, and some people develop a yellow color to the skin (jaundice) because of excess destruction of their red blood cells. They can also experience headaches, loss of appetite, indigestion, a sore tongue, bleeding gums, insomnia (difficulty sleeping), a rapid heartbeat, fatigue, and poor concentration. Some women experience menstrual period irregularities.

Doctors as Detectives: Diagnosing Anemia

Dealing with anemia can be a complex process. Determining if a patient is anemic is easy, but finding the underlying cause can be more difficult.

To test for anemia, a doctor usually orders a complete blood count (CBC). A technician or nurse takes a small sample of blood. The blood is tested for the amount of hemoglobin it contains and the numbers and volume of the different types of blood cells. Some of the blood also is smeared onto a slide so that the size of the cells can be measured and the color and shape of the blood can be gauged.

Once anemia has been confirmed, the doctor has to become a detective. The doctor finds clues by examining the patient and by asking the patient and his or her family about their medical history. Here are some of the questions the doctor may ask:

• What are your symptoms, when did they start, and how long have they lasted?
• Do other people in your family have anemia?
• What illnesses have you had recently?
• What do you eat in your diet?
• Have you recently bled a lot?
• What drugs/medications have you taken recently?

Almost all cases of anemia can be identified by laboratory tests along with the patient’s history and a physical examination.

Because the marrow is where blood cells are made, and it is here that many problems can occur, in a few cases a bone marrow sample may be needed in order to find the cause of the anemia. In this procedure, a needle is inserted into the hip bone to obtain a sample of bone marrow. It is then analyzed for the types and activities of the cells.

Eating Right to Prevent Anemia

Good nutrition plays a big part in preventing or treating many types of anemia. A healthy diet should include eating foods every day that contain:

• Vitamin B12: meat, fish, and dairy (this vitamin is only found in animal products).
• Folic acid: dark green leafy vegetables, meat, eggs, orange juice, and whole-grain cereals.
• Iron: beef; molasses; carob; collards, kale, and turnip greens; dried fruit; dried peas and beans; egg yolks; liver; oysters; potatoes in their skin; pumpkin; sardines; soy flour; spinach; wheat germ; whole grains; iron-fortified cereals.

Anemia is the body’s way of saying that something is wrong, and it should never be ignored. The doctor should always search for the underlying cause of anemia.

Scientific Research

Treatment of anemia depends entirely on the cause. Anemia gets a lot of scientific attention because it is a sign of so many different diseases and disorders. Research is focused both on better ways to diagnose anemia and on developing new ways to treat it. In some cases, anemia is difficult or impossible to treat.

For anemias caused by excessive or chronic bleeding, stopping blood loss is the first step. In some cases, a blood transfusion is used to replenish the volume of blood in the body. For people with dietary causes of anemia, eating a diet rich in the deficient nutrient or taking supplements such as iron or vitamins often fixes the problem.

Treatment for other anemias is more complex. For people with hemolytic anemias, finding out why the red blood cells are being destroyed prematurely is essential. In some people, the spleen must be removed to stop the premature destruction of erythrocytes.

One method of treating certain anemias caused by decreased production of red blood cells is to supply the body with erythropoietin (EPO). Different research groups have manufactured EPO to treat anemias caused by rheumatoid arthritis, HIV, kidney disease, and cancer. Other drugs are aimed at stimulating red cell production in people with sickle cell disease and some types of thalassemia.

See also

Fainting (Syncope)

Resources

Books

Bloom, Miriam. Understanding Sickle-Cell Disease. University Press of Mississippi, 1995.

Davies, Jill. Anemia: A Guide to Causes, Treatment and Prevention. Thorsons Publishers, 1994.

Davies, Jill. Recipes for Health: Anemia. Thorsons Publishers, 1995.

Uthman, Ed. Understanding Anemia. University Press of Mississippi, 1998.

Walker, Dava Jo, Van Wright, Cornelius and Hu, Ying-Hwa. Puzzles. Lollipop Press, 1996. (This is a children’s book about a 9-year-old girl with sickle-cell anemia.)

Organizations

Aplastic Anemia Foundation of America (AAFA, Inc.), P.O. Box 613, Annapolis, MD 21404. The AAFA provides emotional support, patient assistance, funds for research, and educational material about anemia. Telephone 800-747-2820 http://medic.med.uth.tmc.edu/ptnt/00001045.htm

Did You Know?

Cooking acidic foods like tomatoes in cast iron skillets or pans can add significant amounts of iron to the diet.

Sickle Cell Association, Texas Gulf Coast, 2626 South Loop West, Suite 245, Houston, TX 77054. Telephone 713-666-0300 http://www.sicklecell-texas.org

Anemias

Definition

Anemia is a condition characterized by abnormally low levels of healthy red blood cells or hemoglobin (the component of red blood cells that delivers oxygen to tissues throughout the body).

Description

The tissues of the human body need a regular supply of oxygen to stay healthy. Red blood cells, which contain hemoglobin that allows them to deliver oxygen throughout the body, live for only about 120 days. When they die, the iron they contain is returned to the bone marrow and used to create new red blood cells. Anemia develops when heavy bleeding causes significant iron loss or when something happens to slow down the production of red blood cells or to increase the rate at which they are destroyed.

Types of anemia

Anemia can be mild, moderate, or severe enough to lead to life-threatening complications. More than 400 different types of anemia have been identified. Many of them are rare.

IRON DEFICIENCY ANEMIA. Iron deficiency anemia is the most common form of anemia in the world. In the United States, iron deficiency anemia affects about 240,000 toddlers between one and two years of age and 3.3 million women of childbearing age. This condition is less common in older children and in adults over 50 and rarely occurs in teenage boys and young men.

The onset of iron deficiency anemia is gradual and, at first, there may be no symptoms. The deficiency begins when the body loses more iron than it derives from food. Because depleted iron stores cannot meet the body's red blood cell needs, fewer red blood cells develop. In this early stage of anemia, the red blood cells look normal, but they are reduced in number. Then the body tries to compensate for the iron deficiency by producing more red blood cells, which are characteristically smaller in size. Symptoms develop at this stage.

FOLIC ACID DEFICIENCY ANEMIA. Folic acid deficiency anemia is the most common type of megaloblastic anemia (in which red blood cells are bigger than normal). It is caused by a deficiency of folic acid, a vitamin that the body needs to produce normal cells.

Folic acid anemia is especially common in infants and teenagers. Although this condition usually results from a dietary deficiency, it is sometimes due to inability to absorb enough folic acid from such foods as:

• cheese
• eggs
• fish
• green vegetables
• meat
• milk
• mushrooms
• yeast

Smoking raises the risk of developing this condition by interfering with the absorption of vitamin C, which the body needs to absorb folic acid. Folic acid anemia can also be a complication of pregnancy, when a woman's body needs eight times as much folic acid.

VITAMIN B₁₂ DEFICIENCY ANEMIA. Less common in this country than folic acid anemia, vitamin B₁₂ deficiency anemia is another type of megaloblastic anemia that develops when the body doesn't absorb enough of this nutrient. Necessary for the creation of red blood cells, B₁₂ is found in meat and vegetables.

Large amounts of B₁₂ are stored in the body, so this condition may not become apparent until as much as four years after B₁₂ absorption stops or slows down. The resulting drop in red blood cell production can cause:

• loss of muscle control
• loss of sensation in the legs, hands, and feet
• soreness or burning of the tongue
• weight loss

• yellow-blue color blindness

The most common form of B₁₂ deficiency is pernicious anemia. Since most people who eat meat or eggs get enough B₁₂ in their diets, a deficiency of this vitamin usually means that the body is not absorbing it properly. This can occur among people who have had intestinal surgery or among those who do not produce adequate amounts of intrinsic factor, a chemical secreted by the stomach lining that combines with B₁₂ to help its absorption in the small intestine.

Pernicious anemia usually strikes between the ages of 50 and 60. Eating disorders or an unbalanced diet increases the risk of developing pernicious anemia. So do:

• diabetes mellitus
• gastritis, stomach cancer, or stomach surgery
• thyroid disease
• family history of pernicious anemia

VITAMIN C DEFICIENCY ANEMIA. A rare disorder that causes the bone marrow to manufacture abnormally small red blood cells, vitamin C deficiency anemia results from a severe, long-standing dietary deficiency.

HEMOLYTIC ANEMIA. Hemolytic anemia is a condition in which infection or antibodies destroy red blood cells more rapidly than bone marrow can replace them. Some people are born with the disease, while others acquire it later in life.

Hemolytic anemia can enlarge the spleen, accelerating the destruction of red blood cells (hemolysis). Other complications of hemolytic anemia include pain, shock, gallstones, and other serious health problems.

THALASSEMIAS. An inherited form of hemolytic anemia, thalassemia stems from the body's inability to manufacture as much normal hemoglobin as it needs. There are two categories of thalassemia, depending on which of the amino acid chains is affected. (Hemoglobin is composed of four chains of amino acids.) In alpha-thalassemia, there is an imbalance in the production of the alpha chain of amino acids; in beta-thalassemia, there is an imbalance in the beta chain. Alpha-thalassemias most commonly affect blacks (25% have at least one gene); beta-thalassemias most commonly affect people of Mediterranean and Southeast Asian ancestry.

Characterized by production of red blood cells that are unusually small and fragile, thalassemia only affects people who inherit the gene for it from each parent (autosomal recessive inheritance).

AUTOIMMUNE HEMOLYTIC ANEMIAS. Warm antibody hemolytic anemia is the most common type of this disorder. This condition occurs when the body produces autoantibodies that coat red blood cells. The coated cells are destroyed by the spleen, liver, or bone marrow.

Warm antibody hemolytic anemia is more common in women than in men. About one-third of patients who have warm antibody hemolytic anemia also have lymphoma, leukemia, lupus, or connective tissue disease.

In cold antibody hemolytic anemia, the body attacks red blood cells at or below normal body temperature. The acute form of this condition frequently develops in people who have had pneumonia, mononucleosis, or other acute infections. It tends to be mild and short-lived, and disappears without treatment.

Chronic cold antibody hemolytic anemia is most common in women and most often affects those who are over 40 and who have arthritis. This condition usually lasts for a lifetime, generally causing few symptoms. However, exposure to cold temperatures can accelerate red blood cell destruction, causing fatigue, joint aches, and discoloration of the arms and hands.

SICKLE CELL ANEMIA. Sickle cell anemia is a chronic, incurable condition that causes the body to produce defective hemoglobin, which forces red blood cells to assume an abnormal crescent shape. Unlike normal oval cells, fragile sickle cells can't hold enough hemoglobin to nourish body tissues. The deformed shape makes it hard for sickle cells to pass through narrow blood vessels. When capillaries become obstructed, a life-threatening condition called sickle cell crisis is likely to occur.

Sickle cell anemia is hereditary. Its rate of incidence is highest among those of African descent, although it can occur in peoples around the world. A child who inherits the sickle cell gene from each parent will have the disease. A child who inherits the sickle cell gene from only one parent carries the sickle cell trait, but does not have the disease.

APLASTIC ANEMIA. Sometimes curable by bone marrow transplant, but potentially fatal, aplastic anemia is characterized by decreased production of red and white blood cells and platelets (disc-shaped cells that allow the blood to clot). This disorder may be inherited or acquired as a result of recent severe illness, long-term exposure to industrial chemicals, and use of anticancer drugs and certain other medications.

SIDEROBLASTIC ANEMIA. Sideroblastic anemia results from an enzyme disorder in which the body has adequate iron but is unable to incorporate it into hemoglobin. In sideroblastic anemia, iron enters a developing red blood cell and builds up in mitochondria of the cell. This build-up of iron gives the cell nucleus a ringed appearance, and the cell is called a ringed sideroblast, the primary sign of siderblastic anemia. Ringed sideroblasts develop poorly or not at all into mature red blood cells, and the red blood cells cannot properly transport oxygen to tissues throughout the body. X-linked sideroblastic anemia is the hereditary form of sideroblastic anemia, also known as iron overload anemia or sideroblastosis. Another, more common type of sideroblastic anemia is called acquired sideroblastic anemia, which can result from prolonged exposure to toxins or nutritional imbalances. Other causes may be inflammatory disease, cancerous conditions such as leukemia and lymphoma, kidney disorders causing uremia, endocrine disorders, or metabolic disorders.

ANEMIA OF CHRONIC DISEASE. Cancer, chronic infection or inflammation, and kidney and liver disease often cause mild or moderate anemia. Chronic liver failure generally produces the most severe symptoms.

Causes and symptoms

Anemia is caused by bleeding, decreased red blood cell production, or increased red blood cell destruction. Poor diet can contribute to vitamin deficiency and iron deficiency anemias in which fewer red blood cells are produced. Hereditary disorders and certain diseases can cause increased blood cell destruction. However, excessive bleeding is the most common cause of anemia, and the speed with which blood loss occurs has a significant effect on the severity of symptoms. Chronic blood loss is usually a consequence of:

• cancer
• gastrointestinal tumors
• diverticulosis
• polyposis
• heavy menstrual flow
• hemorrhoids
• nosebleeds
• stomach ulcers
• long-standing alcohol abuse

Acute blood loss is usually the result of:

• childbirth
• miscarriage of pregnancy
• injury
• a ruptured blood vessel
• surgery

When a large volume of blood is lost within a short time, blood pressure and the amount of oxygen in the body drop suddenly. Heart failure and death can follow.

Loss of even one-third of the body's blood volume in the space of several hours can be fatal. More gradual blood loss is less serious, because the body has time to create new red blood cells to replace those that have been lost.

Symptoms

Weakness, fatigue, and a run-down feeling may be signs of mild anemia. Skin that is pasty or sallow, or lack of color in the creases of the palm, gums, nail beds, or linings of the eyelids are other signs of anemia. Someone who is weak, tires easily, is often out of breath, and feels faint or dizzy may be severely anemic.

Other symptoms of anemia are:

• angina pectoris (chest pain, often accompanied by a choking sensation that provokes severe anxiety)
• cravings for ice, paint, or dirt (called pica)
• headache
• inability to concentrate, memory loss
• inflammation of the mouth (stomatitis ) or tongue (glossitis)
• insomnia
• irregular heartbeat
• loss of appetite
• nails that are dry, brittle, or ridged
• rapid breathing
• sores in the mouth, throat, or rectum
• sweating
• swelling of the hands and feet
• thirst
• tinnitus (ringing in the ears)
• unexplained bleeding or bruising

In pernicious anemia, the tongue feels unusually slick. A patient with pernicious anemia may have problems with movement or balance, tingling in the hands and feet, confusion, depression, and memory loss.

Pernicious anemia can damage the spinal cord. A doctor should be notified whenever symptoms of this condition occur.

A doctor should also be notified if a patient who has been taking iron supplements develops diarrhea, cramps, or vomiting.

Diagnosis

Personal and family health history may suggest the presence of certain types of anemia. Laboratory tests that measure the percentage of red blood cells or the amount of hemoglobin in the blood are used to confirm diagnosis and determine which type of anemia is responsible for a patient's symptoms. X rays and examinations of bone marrow may be used to identify the source of bleeding.

Treatment

Anemia due to nutritional deficiencies can usually be treated at home with appropriate supplements, under a health professional's guidance. People with iron deficiency should take iron supplements. People with folic acid anemia should take oral folic acid replacements. Vitamin C deficiency anemia can be cured by the recommended daily allowance of vitamin C. People with pernicious anemia may be able to self-administer injections of vitamin B₁₂.

Surgery may be necessary to treat anemia caused by excessive loss of blood. Transfusions of red blood cells may be used to accelerate production of red blood cells in the body.

Medication or surgery may also be necessary to control heavy menstrual flow, repair a bleeding ulcer, or remove polyps (growths or nodules) from the bowels.

Patients with thalassemia usually do not require treatment. However, people with a severe form may require periodic hospitalization for blood transfusions or bone marrow transplantation.

Alternative therapies for iron deficiency anemia focus on adding iron-rich foods to the diet or on techniques to improve circulation and digestion. Herbal remedies to improve digestion include Gentian (Gentiana lutea), which is widely used in Europe to treat anemia and other nutritionally based disorders, as well as anise (Pimpinella anisum), caraway (Carum carvi), cumin (Cuminum cyminum), and licorice.

SICKLE CELL ANEMIA. Treatment for sickle cell anemia involves regular eye examinations, immunizations for pneumonia and infectious diseases, and prompt treatment for sickle cell crises and infections of any kind. Psychotherapy or counseling may help patients deal with the emotional impact of this condition.

VITAMIN B₁₂ DEFICIENCY ANEMIA. A life-long regimen of B₁₂ shots is necessary to control symptoms of pernicious anemia. The patient may be advised to limit physical activity until treatment restores strength and balance.

APLASTIC ANEMIA. People who have aplastic anemia are especially susceptible to infection. Treatment for aplastic anemia may involve blood transfusions and bone marrow transplant to replace malfunctioning cells with healthy ones.

SIDEROBLASTIC ANEMIA. X-linked sideroblastic anemia often improves with pyridoxine (vitamin B₆) therapy. In cases of extreme anemia, whole red blood cell transfusion may be required.

If anemia is acquired, removal of the offending agent or treatment for the primary disorder may allow the anemia to disappear.

ANEMIA OF CHRONIC DISEASE. There is no specific treatment for anemia associated with chronic disease, but treating the underlying illness may alleviate this condition. This type of anemia rarely becomes severe. If it does, transfusions or hormone treatments to stimulate red blood cell production may be prescribed.

HEMOLYTIC ANEMIA. There is no specific treatment for cold-antibody hemolytic anemia. About one-third of patients with warm-antibody hemolytic anemia respond well to large doses of intravenous and oral corticosteroids, which are gradually discontinued as the patient's condition improves. Patients with this condition who don't respond to medical therapy must have the spleen surgically removed. This operation controls anemia in about half of the patients on whom it's performed. Immune system suppressants are prescribed for patients whose surgery is not successful.

Self-care

Anyone who has anemia caused by poor nutrition should modify his or her diet to include more vitamins, minerals, and iron. Vitamin C can stimulate iron absorption. The following foods are also good sources of iron:

• almonds
• broccoli
• dried beans
• dried fruits
• enriched breads and cereals

• lean red meat
• liver
• potatoes
• poultry
• rice
• shellfish
• tomatoes

Because light and heat destroy folic acid, fruits and vegetables should be eaten raw, or cooked as little as possible.

Health care team roles

Often, anemia is not discovered until blood tests are run as part of a routine physical examination. Hemoglobin tests are commonly run by medical technologists or other laboratory professionals. Nurses and allied health professionals can play a critical role in the well-being and quality of life of patients at risk for anemia by understanding erythropoiesis, pathophysiology, nursing assessment (including laboratory data assessment), and nursing interventions related to anemia. In particular, nurses should be sure that patients are educated about their disease and about the treatment options available. In cases where anemia may be inherited, they may provide patients with information about genetic testing. They may also refer patients to professional genetic counselors.

Prognosis

Folic acid and iron deficiency anemias

It usually takes three to six weeks to correct folic acid or iron deficiency anemia. Patients should continue taking supplements for another six months to replenish iron reserves and should have periodic blood tests to make sure the bleeding has stopped and the anemia has not recurred.

Pernicious anemia

Although pernicious anemia is considered incurable, regular B₁₂ shots will alleviate symptoms and reverse complications. Some symptoms will disappear almost as soon as treatment begins.

Aplastic anemia

Aplastic anemia can sometimes be cured by bone marrow transplantation. If the condition is due to immunosuppressive drugs, symptoms may disappear after the drugs are discontinued.

Sickle cell anemia

Although sickle cell anemia cannot be cured, effective treatments enable patients with this disease to enjoy longer, more productive lives.

Thalassemia

People with mild thalassemia (alpha thalassemia trait or beta thalassemia minor) lead normal lives and do not require treatment. Those with severe thalassemia may require bone marrow transplantation. Genetic therapy is being investigated and may soon be available.

Hemolytic anemia

Acquired hemolytic anemia can generally be cured when the cause is removed.

Health care team roles

Anemia is often overlooked as a priority associated with quality patient care. Identifying the underlying causes of anemia in patients is critical to positive care outcomes and requires early assessment and intervention. The entire health care team plays a critical role in the well-being and quality of life of patients with anemia by understanding the disease and appropriate treatments, and by providing patients with any materials and education needed to understand the disease and its treatment.

Prevention

Inherited anemias cannot be prevented. Genetic counseling can help parents cope with questions and concerns about transmitting disease-causing genes to their children.

Avoiding excessive use of alcohol, eating a balanced diet that contains plenty of iron-rich foods, and taking a daily multivitamin can help prevent anemia.

Methods of preventing specific types of anemia include:

• Avoiding lengthy exposure to industrial chemicals and drugs known to cause aplastic anemia.
• Not taking medication that has triggered hemolytic anemia and not eating foods that have caused hemolysis (breakdown of red blood cells).
• Receiving regular B₁₂ shots to prevent pernicious anemia resulting from gastritis or stomach surgery.

KEY TERMS

Aplastic— Exhibiting incomplete or faulty development.

Diabetes mellitus— A disorder of carbohydrate metabolism brought on by a combination of hereditary and environmental factors.

Erythropoiesis— Erythropoiesis is the development of mature red blood cells (erythrocytes).

Hemoglobin— An iron-containing pigment of red blood cells composed of four amino acid chains (alpha, beta, gamma, delta) that delivers oxygen from the lungs to the tissues of the body.

Megaloblast— A large erythroblast (a red marrow cell that synthesizes hemoglobin).

Red blood cells— Yellowish, circular, biconcave disks found in the blood, which contain hemoglobin and carries oxygen. Also known as erythrocytes.

Resources

BOOKS

Ramakrishnan, Usha, ed. Nutritional anemias. London: CRC Press, 2001.

Tierney, Lawrence M., Jr., et al., eds. Current Medical Diagnosis & Treatment. Stamford, CT: Appleton & Lange, 1998.

PERIODICALS

Mahoney, Martin C. "Screening for iron deficiency anemia among children and adolescents." American Family Physician 62:3 (August 1, 2000): 671+.

Sheth, Sujit & Brittenham, Gary M. "Genetic disorders affecting proteins of iron metabolism: Clinical implications. Annual Review of Medicine 51 (2000): 443+.

Worrall, L.M., Tompkins, C.A., & Rust, D.M. "Recognizing and managing anemia." Clinical Journal of Oncology Nursing 3:4 (October 1999): 153+.

ORGANIZATIONS

Aplastic Anemia & MDS International Foundation. P.O. Box 613, Annapolis, MD 21404-0613. (800) 747-2820 or (410) 867-0242. 〈http://www.aplastic.org〉.

Leukemia & Lymphoma Society. 1311 Mamaroneck Ave., White Plains, NY 10605. (914) 949-5213. 〈http://www.leukemia-lymphoma.org〉.

National Heart, Lung, Blood Institute Information Center. P.O. Box 30105, Bethesda, MD 20824-0105. (301) 592-8573. 〈http://www.nhlbi.nih.gov〉.

National Organization for Rare Disorders. P.O. Box 8923, New Fairfield, CT 06812-8923, (203) 746-6518 or (800) 999-6673. 〈http://www.rarediseases.org〉.

OTHER

Iron Disorders Institute. 〈http://www.irondisorders.org〉.

National Center for Biotechnology Information. 〈http://www.ncbi.nlm.nih.gov〉.

Anemias

Definition

Anemia is a condition characterized by abnormally low levels of healthy red blood cells or hemoglobin (the component of red blood cells that delivers oxygen to tissues throughout the body).

Description

The tissues of the human body need a regular supply of oxygen to stay healthy. Red blood cells, which contain hemoglobin that allows them to deliver oxygen throughout the body, live for only about 120 days. When they die, the iron they contain is returned to the bone marrow and used to create new red blood cells. Anemia develops when heavy bleeding causes significant iron loss or when something happens to slow down the production of red blood cells or to increase the rate at which they are destroyed.

Types of anemia

Anemia can be mild, moderate, or severe enough to lead to life-threatening complications. More than 400 different types of anemia have been identified. Many of them are rare.

IRON DEFICIENCY ANEMIA. The onset of iron deficiency anemia is gradual and, at first, there may not be any symptoms. The deficiency begins when the body loses more iron than it derives from food and other sources. Because depleted iron stores cannot meet the red blood cell's needs, fewer red blood cells develop. In this early stage of anemia, the red blood cells look normal, but they are reduced in number. Then the body tries to compensate for the iron deficiency by producing more red blood cells, which are characteristically small in size. Symptoms develop at this stage.

FOLIC ACID DEFICIENCY ANEMIA. Folic acid anemia is especially common in infants and teenagers. Although this condition usually results from a dietary deficiency, it is sometimes due to inability to absorb enough folic acid from such foods as:

• cheese
• eggs
• fish
• green vegetables
• meat
• milk
• mushrooms
• yeast

Smoking raises the risk of developing this condition by interfering with the absorption of Vitamin C, which the body needs to absorb folic acid. Folic acid anemia can be a complication of pregnancy, when a woman's body needs eight times more folic acid than it does otherwise.

VITAMIN B₁₂ DEFICIENCY ANEMIA. Less common in this country than folic acid anemia, vitamin B₁₂ deficiency anemia is another type of megaloblastic anemia that develops when the body doesn't absorb enough of this nutrient. Necessary for the creation of red blood cells, B₁₂ is found in meat and vegetables.

Large amounts of B₁₂ are stored in the body, so this condition may not become apparent until as much as four years after B₁₂ absorption stops or slows down. The resulting drop in red blood cell production can cause:

• loss of muscle control
• loss of sensation in the legs, hands, and feet
• soreness or burning of the tongue
• weight loss
• yellow-blue color blindness

The most common form of B₁₂ deficiency is pernicious anemia. Since most people who eat meat or eggs get enough B₁₂ in their diets, a deficiency of this vitamin usually means that the body is not absorbing it properly. This can occur among people who have had intestinal surgery or among those who do not produce adequate amounts of intrinsic factor, a chemical secreted by the stomach lining that combines with B₁₂ to help its absorption in the small intestine.

Pernicious anemia usually strikes between the ages of 50-60. Eating disorders or an unbalanced diet increase the risk of developing pernicious anemia. So do:

• diabetes mellitus
• gastritis, stomach cancer, or stomach surgery
• thyroid disease
• family history of pernicious anemia

VITAMIN C DEFICIENCY ANEMIA. A rare disorder that causes the bone marrow to manufacture abnormally small red blood cells, Vitamin C deficiency anemia results from a severe, long-standing dietary deficiency.

HEMOLYTIC ANEMIA. Some people are born with hemolytic anemia. Some acquire this condition, in which infection or antibodies destroy red blood cells more rapidly than bone marrow can replace them.

Hemolytic anemia can enlarge the spleen, accelerating the destruction of red blood cells (hemolysis). Other complications of hemolytic anemia include:

• pain
• shock
• gallstones and other serious health problems

KEY TERMS

Aplastic— Exhibiting incomplete or faulty development.

Hemoglobin— An iron-containing pigment of red blood cells composed of four amino acid chains (alpha, beta, gamma, delta) that delivers oxygen from the lungs to the tissues of the body.

Megaloblast— A large erythroblast (a red marrow cell that synthesizes hemoglobin).

THALASSEMIAS. An inherited form of hemolytic anemia, thalassemia stems from the body's inability to manufacture as much normal hemoglobin as it needs. There are two categories of thalassemia, depending on which of the amino acid chains is affected. (Hemoglobin is composed of four chains of amino acids.) In alpha-thalassemia, there is an imbalance in the production of the alpha chain of amino acids; in beta-thalassemia, there is an imbalance in the beta chain. Alpha-thalassemias most commonly affect blacks (25% have at least one gene); beta-thalassemias most commonly affect people of Mediterranean ancestry and Southeast Asians.

Characterized by production of red blood cells that are unusually small and fragile, thalassemia only affects people who inherit the gene for it from each parent (autosomal recessive inheritance).

AUTOIMMUNE HEMOLYTIC ANEMIAS. Warm antibody hemolytic anemia is the most common type of this disorder. This condition occurs when the body produces autoantibodies that coat red blood cells. The coated cells are destroyed by the spleen, liver, or bone marrow.

Warm antibody hemolytic anemia is more common in women than in men. About one-third of patients who have warm antibody hemolytic anemia also have lymphoma, leukemia, lupus, or connective tissue disease.

In cold antibody hemolytic anemia, the body attacks red blood cells at or below normal body temperature. The acute form of this condition frequently develops in people who have had pneumonia, mononeucleosis, or other acute infections. It tends to be mild and short-lived, and disappears without treatment.

Chronic cold antibody hemolytic anemia is most common in women and most often affects those who are over 40 and who have arthritis. This condition usually lasts for a lifetime, generally causing few symptoms. However, exposure to cold temperatures can accelerate red blood cell destruction, causing fatigue, joint aches, and discoloration of the arms and hands.

SICKLE CELL ANEMIA. Sickle cell anemia is a chronic, incurable condition that causes the body to produce defective hemoglobin, which forces red blood cells to assume an abnormal crescent shape. Unlike normal oval cells, fragile sickle cells can't hold enough hemoglobin to nourish body tissues. The deformed shape makes it hard for sickle cells to pass through narrow blood vessels. When capillaries become obstructed, a life-threatening condition called sickle cell crisis is likely to occur.

Sickle cell anemia is hereditary. It almost always affects blacks and people of Mediterranean descent. A child who inherits the sickle cell gene from each parent will have the disease. A child who inherits the sickle cell gene from only one parent carries the sickle cell trait, but does not have the disease.

APLASTIC ANEMIA. Sometimes curable by bone marrow transplant, but potentially fatal, aplastic anemia is characterized by decreased production of red and white blood cells and platelets (disc-shaped cells that allow the blood to clot). This disorder may be inherited or acquired as a result of:

• recent severe illness
• long-term exposure to industrial chemicals
• use of anticancer drugs and certain other medications

ANEMIA OF CHRONIC DISEASE. Cancer, chronic infection or inflammation, and kidney and liver disease often cause mild or moderate anemia. Chronic liver failure generally produces the most severe symptoms. People infected with the Human immunodeficiency virus (HIV) that causes AIDS often face severe fatigue.

Causes and symptoms

Anemia is caused by bleeding, decreased red blood cell production, or increased red blood cell destruction. Poor diet can contribute to vitamin deficiency and iron deficiency anemias in which fewer red blood cells are produced. Hereditary disorders and certain diseases can cause increased blood cell destruction. However, excessive bleeding is the most common cause of anemia, and the speed with which blood loss occurs has a significant effect on the severity of symptoms. Chronic blood loss is usually a consequence of:

• cancer
• gastrointestinal tumors
• diverticulosis
• polyposis
• heavy menstrual flow
• hemorrhoids
• nosebleeds
• stomach ulcers
• long-standing alcohol abuse

Acute blood loss is usually the result of:

• childbirth
• injury
• a ruptured blood vessel
• surgery

When a lot of blood is lost within a short time, blood pressure and the amount of oxygen in the body drop suddenly. Heart failure and death can follow.

Loss of even one-third of the body's blood volume in the space of several hours can be fatal. More gradual blood loss is less serious, because the body has time to create new red blood cells to replace those that have been lost.

Symptoms

Weakness, fatigue, and a run-down feeling may be signs of mild anemia. Skin that is pasty or sallow, or lack of color in the creases of the palm, gums, nail beds, or lining of the eyelids are other signs of anemia. Someone who is weak, tires easily, is often out of breath, and feels faint or dizzy may be severely anemic.

Other symptoms of anemia are:

• angina pectoris (chest pain, often accompanied by a choking sensation that provokes severe anxiety )
• cravings for ice, paint, or dirt
• headache
• inability to concentrate, memory loss
• inflammation of the mouth (stomatitis ) or tongue (glossitis)
• insomnia
• irregular heartbeat
• loss of appetite
• nails that are dry, brittle, or ridged
• rapid breathing
• sores in the mouth, throat, or rectum
• sweating
• swelling of the hands and feet
• thirst
• tinnitus (ringing in the ears)
• unexplained bleeding or bruising

In pernicious anemia, the tongue feels unusually slick. A patient with pernicious anemia may have:

• problems with movement or balance
• tingling in the hands and feet
• confusion, depression, and memory loss

Pernicious anemia can damage the spinal cord. A doctor should be notified whenever symptoms of this condition occur.

A doctor should also be notified if a patient who has been taking iron supplements develops:

• diarrhea
• cramps
• vomiting

Diagnosis

Personal and family health history may suggest the presence of certain types of anemia. Laboratory tests that measure the percentage of red blood cells or the amount of hemoglobin in the blood are used to confirm diagnosis and determine which type of anemia is responsible for a patient's symptoms. X rays and examinations of bone marrow may be used to identify the source of bleeding.

Treatment

Anemia due to nutritional deficiencies can usually be treated at home with iron supplements or self administered injections of vitamin B₁₂. People with folic acid anemia should take oral folic acid replacements. Vitamin C deficiency anemia can be cured by taking one vitamin C tablet a day.

Surgery may be necessary to treat anemia caused by excessive loss of blood. Transfusions of red blood cells may be used to accelerate production of red blood cells.

Medication or surgery may also be necessary to control heavy menstrual flow, repair a bleeding ulcer, or remove polyps (growths or nodules) from the bowels.

Patients with thalassemia usually do not require treatment. However people with a severe form may require periodic hospitalization for blood transfusions and/or bone marrow transplantation.

SICKLE CELL ANEMIA. Treatment for sickle cell anemia involves regular eye examinations, immunizations for pneumonia and infectious diseases, and prompt treatment for sickle cell crises and infections of any kind. Psychotherapy or counseling may help patients deal with the emotional impact of this condition.

VITAMIN B₁₂ DEFICIENCY ANEMIA. A life-long regimen of B₁₂ shots is necessary to control symptoms of pernicious anemia. The patient may be advised to limit physical activity until treatment restores strength and balance.

APLASTIC ANEMIA. People who have aplastic anemia are especially susceptible to infection. Treatment for aplastic anemia may involve blood transfusions and bone marrow transplant to replace malfunctioning cells with healthy ones.

ANEMIA OF CHRONIC DISEASE. There is no specific treatment for anemia associated with chronic disease, but treating the underlying illness may alleviate this condition. Erythropoietin is a hormone that stimulates production of red blood cells. It is sometimes used to treat anemia from kidney disease or cancer chemotherapy. This type of anemia rarely becomes severe. If it does, transfusions or hormone treatments to stimulate red blood cell production may be prescribed. A working group met in 2004 to address the specific management of anemia in patients infected with HIV.

HEMOLYTIC ANEMIA. There is no specific treatment for cold-antibody hemolytic anemia. About one-third of patients with warm-antibody hemolytic anemia respond well to large doses of intravenous and oral corticosteroids, which are gradually discontinued as the patient's condition improves. Patients with this condition who don't respond to medical therapy must have the spleen surgically removed. This operation controls anemia in about one-half of the patients on whom it's performed. Immune-system suppressants are prescribed for patients whose surgery is not successful.

Self-care

Anyone who has anemia caused by poor nutrition should modify his or her diet to include more vitamins, minerals, and iron. Vitamin C can stimulate iron absorption. The following foods are also good sources of iron:

• almonds
• broccoli
• dried beans
• dried fruits
• enriched breads and cereals
• lean red meat
• liver
• potatoes
• poultry
• rice
• shellfish
• tomatoes

Because light and heat destroy folic acid, fruits and vegetables should be eaten raw or cooked as little as possible.

Alternative treatment

As is the case in standard medical treatment, the cause of the specific anemia will determine the alternative treatment recommended. If the cause is a deficiency, for example iron deficiency, folic acid deficiency, B₁₂ deficiency, or vitamin C deficiency, supplementation is the treatment. For extensive blood loss, the cause should be identified and corrected. Other types of anemias should be addressed on a deep healing level with crisis intervention when necessary.

Many alternative therapies for iron-deficiency anemia focus on adding iron-rich foods to the diet or on techniques to improve circulation and digestion. Iron supplementation, especially with iron citrate (less likely to cause constipation ), is used by alternative practitioners. This can be given in combination with herbs that are rich in iron. Some examples of iron-rich herbs are dandelion (Taraxacum officinale ), parsley (Petroselinum crispum ), and nettle (Urtica dioica ). The homeopathic remedy ferrum phosphoricum can also be helpful.

An iron-rich herbal tonic can also me made using the following recipe:

• soak 1/2 oz of yellow dock root and 1/2 oz dandelion root in 1 qt of boiled water for four to 8 hours
• strain and simmer until the amount of liquid is reduced to 1 cup
• remove from heat and add 1/2 cup black strap molasses, mixing well
• store in refrigerator; take 1 tsp-2 Tbsp daily

Other herbal remedies used to treat iron-deficiency anemia aim to improve the digestion. Gentian (Gentiana lutea ) is widely used in Europe to treat anemia and other nutritionally based disorders. The bitter qualities of gentian help stimulate the digestive system, making iron and other nutrients more available for absorption. This bitter herb can be brewed into tea or purchased as an alcoholic extract (tincture).

Other herbs recommended to promote digestion include:

• anise (Pimpinella anisum )
• caraway (Carum carvi )
• cumin (Cuminum cyminum )
• linden (Tilia spp.)
• licorice (Glycyrrhiza glabra )

Traditional Chinese treatments for anemia include:

• acupuncture to stimulate a weakened spleen
• asian ginseng (Panax ginseng ) to restore energy
• dong quai (Angelica sinensis ) to control heavy menstrual bleeding
• a mixture of dong quai and Chinese foxglove (Rehmannia glutinosa ) to clear a sallow complexion

Prognosis

Folic-acid and iron-deficiency anemias

It usually takes three to six weeks to correct folic acid or iron deficiency anemia. Patients should continue taking supplements for another six months to replenish iron reserves. They should have periodic blood tests to make sure the bleeding has stopped and the anemia has not recurred.

Pernicious anemia

Although pernicious anemia is considered incurable, regular B₁₂ shots will alleviate symptoms and reverse complications. Some symptoms will disappear almost as soon as treatment begins.

Aplastic anemia

Aplastic anemia can sometimes be cured by bone marrow transplantation. If the condition is due to immunosuppressive drugs, symptoms may disappear after the drugs are discontinued.

Sickle cell anemia

Although sickle cell anemia cannot be cured, effective treatments enable patients with this disease to enjoy longer, more productive lives.

Thalassemia

People with mild thalassemia (alpha thalassemia trait or beta thalassemia minor) lead normal lives and do not require treatment. Those with severe thalassemia may require bone marrow transplantation. Genetic therapy is is being investigated and may soon be available.

Hemolytic anemia

Acquired hemolytic anemia can generally be cured when the cause is removed.

Prevention

Inherited anemias cannot be prevented. Genetic counseling can help parents cope with questions and concerns about transmitting disease-causing genes to their children.

Avoiding excessive use of alcohol, eating a balanced diet that contains plenty of iron-rich foods, and taking a daily multivitamin can help prevent anemia.

Methods of preventing specific types of anemia include:

• avoiding lengthy exposure to industrial chemicals and drugs known to cause aplastic anemia
• not taking medication that has triggered hemolytic anemia and not eating foods that have caused hemolysis (breakdown of red blood cells)
• receiving regular B12 shots to prevent pernicious anemia resulting from gastritis or stomach surgery

Resources

PERIODICALS

"Biopharmaceuitcal Company Announces Manufacturing Agreement for Anemia Drug." Obesity, Wellness, & Fitness Week (September 4, 2004): 406.

"Management Strategy for Anemia in HIV Infection Elucidated." Immunotherapy Weekly (July 7, 2004): 75.

Anemia

Definition

Anemia is a condition characterized by abnormally low levels of healthy red blood cells or hemoglobin.

Description

The tissues of the human body need a regular supply of oxygen to stay healthy. Red blood cells, which contain hemoglobin that allows them to deliver oxygen throughout the body, live for only about 120 days. When they die, the iron they contain is returned to the bone marrow and used to create new red blood cells. Anemia can develop when heavy bleeding causes significant iron loss. It also occurs when something happens to slow down the production of red blood cells or to increase the rate at which they are destroyed.

Anemia can be mild, moderate, or severe enough to lead to life-threatening complications. Over 400 different types of anemia have been identified. Many of them are rare. More common anemia types include:

• iron deficiency anemia
• folic acid deficiency anemia
• vitamin B ₁₂ deficiency anemia
• vitamin C deficiency anemia
• autoimmune hemolytic anemia
• hemolytic anemia
• sickle cell anemia
• aplastic anemia
• anemia of chronic disease

Causes & symptoms

Anemia is caused by bleeding, decreased red blood cell production, or increased red blood cell destruction. Poor diet can contribute to vitamin deficiency and iron deficiency anemia, in which fewer red blood cells are produced. Hereditary disorders and certain diseases can cause increased blood cell destruction. However, excessive bleeding is the most common cause of anemia, and the speed with which blood loss occurs has a significant effect on the severity of symptoms. Chronic blood loss may be caused by:

• heavy menstrual flow
• hemorrhoids
• nosebleeds
• cancer
• gastrointestinal tumors
• diverticulosis
• polyposis
• stomach ulcers
• long-term alcohol abuse

Acute blood loss is usually the result of:

• childbirth
• injury
• ruptured blood vessel
• surgery

Iron deficiency anemia

Iron deficiency anemia is the most common form of anemia in the world. In the United States, iron deficiency anemia affects about 240,000 toddlers between one and two years of age and 3.3 million women of childbearing age. This condition is less common in older children and in adults over 50, and it rarely occurs in teenage boys and young men.

The onset of iron deficiency anemia is gradual. The deficiency begins when the body loses more iron than it gains from food and other sources. Because depleted iron stores cannot meet the red blood cells' needs, fewer red blood cells develop. In this early stage of anemia, the red blood cells look normal, but they are reduced in number. Then the body tries to compensate for the iron deficiency by producing more red blood cells, which are characteristically small in size.

Weakness, fatigue , and a run-down feeling may be signs of mild anemia. Other signs include skin that is pasty or sallow, or lack of color in the creases of the palm, gums, nail beds, or lining of the eyelids. Someone who is weak, tires easily, is often out of breath, and feels faint or dizzy may be severely anemic. Other symptoms of anemia are:

• angina pectoris (chest pain )
• headache
• inability to concentrate and/or memory loss
• inflammation of the mouth (stomatitis) or tongue (glossitis)
• insomnia
• irregular heartbeat
• loss of appetite
• nails that are dry, brittle, or ridged
• rapid breathing
• sores in the mouth, throat, or rectum
• sweating
• swelling of the hands and feet
• thirst
• tinnitus (ringing in the ears)
• unexplained bleeding or bruising
• pica (a craving to chew ice, paint, or dirt)

Folic acid deficiency anemia

Folic acid deficiency anemia is the most common type of megaloblastic anemia, in which red blood cells are bigger than normal. It is caused by a deficiency of folic acid, a vitamin that the body needs to produce normal cells.

Folic acid anemia is especially common in infants and teenagers. Although this condition usually results from a dietary deficiency, it is sometimes due to an inability to absorb enough folic acid from foods such as:

• eggs
• fish
• green vegetables
• meat
• milk and cheese
• mushrooms
• yeast

Smoking raises the risk of developing this condition by interfering with the absorption of vitamin C, which the body needs to absorb folic acid. Folic acid anemia can be a complication of pregnancy , when a woman's body needs eight times more folic acid than it does otherwise.

Vitamin B₁₂ deficiency anemia

Less common in this country than folic acid anemia, vitamin B₁₂ deficiency anemia is another type of megaloblastic anemia that develops when the body does not absorb enough of this nutrient. Necessary for the creation of red blood cells, B₁₂ is found in meat and vegetables.

Large amounts of B₁₂ are stored in the body, so this condition may not become apparent until as long as four years after B₁₂ absorption slows down or stops. The resulting drop in red blood cell production can cause:

• loss of muscle control
• loss of sensation in the legs, hands, and feet
• soreness or burning of the tongue
• weight loss
• yellow-blue color blindness

The most common form of B₁₂ deficiency is pernicious anemia. Since most people who eat meat or eggs get enough B₁₂ in their diets , a deficiency of this vitamin usually means that the body is not absorbing it properly. This can occur among people who have had intestinal surgery or those who do not produce adequate amounts of intrinsic factor, a chemical secreted by the stomach lining that combines with B₁₂ to help its absorption in the small intestine. Symptoms of pernicious anemia include problems with movement or balance, a slick tongue, tingling in the hands and feet, confusion, depression , and memory loss. Pernicious anemia can also damage the spinal cord. A doctor should be notified whenever symptoms of this condition occur.

Pernicious anemia usually strikes people 50–60 years of age. Eating disorders or an unbalanced diet increases the risk of developing pernicious anemia. So do diabetes mellitus, gastritis , stomach cancer, stomach surgery, thyroid disease, and family history of pernicious anemia.

Vitamin C deficiency anemia

A rare disorder that causes the bone marrow to manufacture abnormally small red blood cells, vitamin C deficiency anemia results from a severe, long-standing dietary deficiency.

Hemolytic anemia

Some people are born with hemolytic anemia. Some acquire this condition, in which infection or antibodies destroy red blood cells more rapidly than bone marrow can replace them.

Hemolytic anemia can enlarge the spleen and accelerate the destruction of red blood cells (hemolysis). Other complications of hemolytic anemia may include pain, shock, gallstones , and other serious health problems.

Thalassemias

An inherited form of hemolytic anemia, thalassemia stems from the body's inability to manufacture as much normal hemoglobin as it needs. There are two categories of thalassemia, depending on which of the amino acid chains is affected. (Hemoglobin is composed of four chains of amino acids.) In alpha-thalassemia, there is an imbalance in the production of the alpha chain of amino acids ; in beta-thalassemia, there is an imbalance in the beta chain. Alpha-thalassemias most commonly affect blacks (25% have at least one gene); beta-thalassemias most commonly affect people of Mediterranean and Southeast Asian ancestry.

Characterized by production of red blood cells that are unusually small and fragile, thalassemia only affects people who inherit the gene for it from each parent (autosomal recessive inheritance).

Autoimmune hemolytic anemia

Warm antibody hemolytic anemia is the most common type of this disorder. This condition occurs when the body produces autoantibodies that coat red blood cells. The coated cells are destroyed by the spleen, liver, or bone marrow.

Warm antibody hemolytic anemia is more common in women than in men. About one-third of patients who have warm antibody hemolytic anemia also have lymphoma, leukemia , lupus, or connective tissue disease.

In cold antibody hemolytic anemia, the body attacks red blood cells at or below normal body temperature. The acute form of this condition frequently develops in people who have had pneumonia, mononucleosis , or other acute infections . It tends to be mild and short-lived, and disappears without treatment.

Chronic cold antibody hemolytic anemia is most common in women and most often affects those who are over 40 and have arthritis. This condition usually lasts for a lifetime, generally causing few symptoms. However, exposure to cold temperatures can accelerate red blood cell destruction, causing fatigue, joint aches, and discoloration of the arms and hands.

Sickle cell anemia

Sickle cell anemia is a chronic, incurable condition that causes the body to produce defective hemoglobin, which forces red blood cells to assume an abnormal crescent shape. Unlike normal oval cells, fragile sickle cells cannot hold enough hemoglobin to nourish body tissues. The deformed shape makes it hard for sickle cells to pass through narrow blood vessels. When capillaries become obstructed, a life-threatening condition called sickle cell crisis is likely to occur.

Sickle cell anemia is hereditary. It almost always affects people of African or Mediterranean descent. A child who inherits the sickle cell gene from each parent will have the disease, but a child who inherits the gene from only one parent will carry the sickle cell trait, but will not have the disease.

Aplastic anemia

Sometimes curable by bone marrow transplant, but potentially fatal, aplastic anemia is characterized by decreased production of red and white blood cells and platelets (disc-shaped cells that allow the blood to clot). This disorder may be inherited or acquired as a result of recent severe illness, long-term exposure to industrial chemicals, or use of anticancer drugs and certain other medications.

Anemia of chronic disease

Cancer, chronic infection or inflammation, and kidney and liver disease often cause mild or moderate anemia. Chronic liver failure generally produces the most severe symptoms.

Diagnosis

Personal and family health history may suggest the presence of certain types of anemia. Laboratory tests that measure the percentage of red blood cells or the amount of hemoglobin in the blood are used to confirm diagnosis and determine which type of anemia is responsible for a patient's symptoms. X rays and examinations of bone marrow may be used to identify the source of bleeding.

Treatment

Anyone who has anemia caused by poor nutrition should modify his or her diet to include more vitamins, minerals, and iron. Foods such as lean red meats, dried beans and fruits, liver, poultry, and enriched breads and cereals are all good sources of iron. In addition, eating foods rich in vitamin C such as citrus fruits and juices can promote the absorption of iron.

Patients diagnosed with iron-deficiency anemia should undergo a thorough physical examination and medical history to determine the cause of the anemia, particularly if chronic or acute blood loss is suspected. The cause of a specific anemia will determine the type of treatment recommended.

Anemia due to nutritional deficiencies can usually be treated at home with iron supplements or self administered injections of vitamin B₁₂. People with folic acid anemia should take oral folic acid replacements. Vitamin C deficiency anemia can be cured by taking daily supplements of vitamin C.

Many therapies for iron-deficiency anemia focus on adding iron-rich foods to the diet or on techniques to improve circulation and digestion. Iron supplementation, especially with iron citrate (less likely to cause constipation ), can be given in combination with herbs that are rich in iron. Some examples of iron-rich herbs are dandelion (Taraxacum officinale ), parsley (Petroselinum crispum ), and nettle (Urtica dioica ). The homeopathic remedy ferrum phosphoricum (iron sulfate) can also be helpful.

An iron-rich herbal tonic can also be made using the following recipe:

• Soak one-half ounce of yellow dock root and one-half ounce dandelion root in 1 qt of boiled water for 4–8 hours.
• Simmer until the amount of liquid is reduced to 1 cup.
• Remove from heat and add one-half cup black strap molasses, mixing well.
• Store in refrigerator; take one-quarter cup daily.

Other herbal remedies known to promote digestion are prescribed to treat iron-deficiency anemia. Gentian (Gentiana lutea ) is widely used in Europe to treat anemia and other nutritionally-based disorders. The bitter qualities of gentian help stimulate the digestive system, making iron and other nutrients more available for absorption. This bitter herb can be brewed into tea or purchased as an alcoholic extract (tincture).

Other herbs recommended to promote digestion include:

• anise (Pimpinella anisum )
• caraway (Carum carvi )
• cumin (Cuminum cyminum )
• linden (Tilia spp.)
• licorice (Glycyrrhiza glabra )

Traditional Chinese treatments for anemia include:

• acupuncture to stimulate a weakened spleen
• asian ginseng (Panax ginseng ) to restore energy
• dong quai (Angelica sinensis ) to control heavy menstrual bleeding
• a mixture of dong quai and Chinese foxglove (Rehmannia glutinosa ) to clear a sallow complexion
• astragalus (Astragalus membranaceus ) to treat pallor and dizziness

Allopathic treatment

Surgery may be necessary to treat anemia caused by excessive loss of blood. Transfusions of red blood cells may be used to accelerate production of red blood cells.

Medication or surgery may also be necessary to control heavy menstrual flow, repair a bleeding ulcer, or remove polyps (growths or nodules) from the bowels.

Patients with thalassemia usually do not require treatment. However people with a severe form may require periodic hospitalization for blood transfusions and/or bone marrow transplantation.

Sickle cell anemia

Treatment for sickle cell anemia involves regular eye examinations, immunizations for pneumonia and infectious diseases, and prompt treatment for sickle cell crises and infections of any kind. Psychotherapy or counseling may help patients deal with the emotional impact of this condition.

Vitamin B₁₂ deficiency anemia

A life-long regimen of B₁₂ shots is necessary to control symptoms of pernicious anemia. The patient may be advised to limit physical activity until treatment restores strength and balance.

Aplastic anemia

People who have aplastic anemia are especially susceptible to infection. Treatment for aplastic anemia may involve blood transfusions and bone marrow transplant to replace malfunctioning cells with healthy ones.

Anemia of chronic disease

There is no specific treatment for anemia associated with chronic disease, but treating the underlying illness may alleviate this condition. This type of anemia rarely becomes severe. If it does, transfusions or hormone treatments to stimulate red blood cell production may be prescribed.

Hemolytic anemia

There is no specific treatment for cold-antibody hemolytic anemia. About one-third of patients with warm-antibody hemolytic anemia respond well to large doses of intravenous and oral corticosteroids, which are gradually discontinued as the patient's condition improves. Patients with this condition who do not respond to medical therapy must have the spleen surgically removed. This operation controls anemia in about half of the patients on whom it is performed. Immune-system suppressants are prescribed for patients whose surgery is not successful.

Expected results

Folic acid and iron deficiency anemia

It usually takes three to six weeks to correct folic acid or iron deficiency anemia. Patients should continue taking supplements for another six months to replenish iron reserves and should have periodic blood tests to make sure the bleeding has stopped and the anemia has not recurred.

Pernicious anemia

Although pernicious anemia is considered incurable, regular B₁₂ shots will alleviate symptoms and reverse complications. Some symptoms will disappear almost as soon as treatment begins.

Aplastic anemia

Aplastic anemia can sometimes be cured by a bone marrow transplant. If the condition is due to immunosuppressive drugs, symptoms may disappear after the drugs are discontinued.

Sickle cell anemia

Although sickle cell anemia cannot be cured, effective treatments enable patients with this disease to enjoy longer, more productive lives.

Thalassemia

People with mild thalassemia (alpha thalassemia trait or beta thalassemia minor) lead normal lives and do not require treatment. Those with severe thalassemia may require bone marrow transplantation. Genetic therapy is being investigated and may soon be available.

Hemolytic anemia

Acquired hemolytic anemia can generally be cured when the cause is removed.

Prevention

Inherited anemia cannot be prevented. Genetic counseling can help parents cope with questions and concerns about passing on disease-causing genes to their children.

Avoiding excessive use of alcohol, eating a balanced diet that contains plenty of iron-rich foods, and taking a daily multivitamin can help prevent anemia.

Methods of preventing specific types of anemia include:

• Avoiding lengthy exposure to industrial chemicals and drugs known to cause aplastic anemia.
• Not taking medication that has triggered hemolytic anemia and not eating foods that have caused hemolysis (breakdown of red blood cells).
• Receiving regular B₁₂ shots to prevent pernicious anemia resulting from gastritis or stomach surgery.

Resources

BOOKS

Fauci, Anthony S. et al., eds. Harrison's Principles of Internal Medicine. New York: McGraw-Hill, 1998.

Tierney, Lawrence M., Jr. Current Medical Diagnosis & Treatment, 1998. Stamford, Conn.: Appleton & Lange, 1998.

Paula Ford-Martin