Hair is said to be a person’s crowning glory. Most of the hair on a person’s head is growing constantly. Scalp hair grows about half an inch per month, although this growth rate slows as people age. The growth stage lasts for 2 to 6 years. It is followed by a resting stage, lasting for 2 to 3 months, during which the hair still is attached but no longer grows. After the resting stage, the hair falls out, and a new hair starts to form in the same spot. The average person loses about 50 to 100 hairs a day as part of this normal cycle. Hair loss occurs when people lose more hairs than normal each day or when new hairs do not grow to replace the lost ones.

How Does Hair Grow?

To understand hair loss, it helps to know something about how hair is formed. Hair is made of keratin (KER-a-tin), the same protein that makes up nails and the outer layer of skin. The part of a hair that shows is called the hair shaft. Below the skin is the hair root, which is enclosed in the follicle (FOL-i-kul), a tiny, bulb-shaped structure. The root is alive, but the shaft is composed of dead tissue made by the follicle.

What Is Hair Loss?

Hair loss refers to the partial or total loss of hair from part of the body where normally it grows, especially the scalp. Alopecia (AL-o-PEE-sha) is the medical term for baldness, which is the loss of all or a significant part of the scalp hair. Unlike other parts of the body, hair is mostly decorative. Losing hair is not a medical problem in itself, although, in some cases, it can be a sign of illness. Many people are perfectly comfortable being bald. However, others feel that hair loss makes them less attractive.

What Causes Hair Loss?

More than 40 million men and 20 million women in the United States have some hair loss. It is quite normal for both men and women to see some thinning of their scalp hair as they get older. However, hair loss can occur for a number of other reasons as well. Following are some forms of hair loss and their causes.

Common baldness

Loss of scalp hair due to aging affects most people of both sexes sooner or later. At least 95 percent of hair loss is of this kind. The condition is caused by a combination of age, genetics, and certain hormones* called androgens (AN-dro-jenz). These last two factors give the condition its medical name: androgenetic (AN-dro-je-NET-ik) alopecia. In men, the condition usually starts with a hairline that keeps moving higher, followed by a thin or bald spot that appears on top of the head. Eventually, all that may be left is a horseshoe-shaped fringe of hair around the sides and back of the head. This is known as male-pattern baldness. In women, the condition usually leads to thinning of the hair over the whole head. This is especially common after menopause*. It is known as female-pattern baldness.

* hormones: are chemicals that are produced by different glands in the body. Hormones are like the body’s ambassadors: they are created in one place but are sent through the body to have specific regulatory effects in different places.

* menopause: (MEN-oh-pawz) is the time in a woman’s life when she stops having periods and can no longer become pregnant.

Alopecia areata

Alopecia areata (ar-ee-AY-ta) can strike people of any age, including children and young adults. This condition leads to sudden hair loss, often in round patches on the scalp about the size of a coin or larger. In severe cases, the hair may fall out from the whole head, including the eyebrows and beard, or the whole body. Alopecia areata may be caused by a problem with the immune system* in which immune cells attack the body’s own follicles, for reasons that are not clear. The hair usually grows back on its own within 6 to 24 months.

* immune system: is the body system that fights disease.

Medical problems

Several medical conditions and treatments can cause hair loss in people of all ages and both sexes. Sometimes, people notice a lot of hair falling out within 1 to 3 months after having a high fever, a severe infection, or a major operation. Some women also lose a large amount of hair within a few months after giving birth. In addition, an overactive or underactive thyroid gland* can cause hair loss, as can ringworm (a fungus* infection) of the scalp. People with cancer often lose their hair during chemotherapy*. Other medications may cause hair loss as well, including blood thinners, birth control pills, and medicines for depression* and high blood pressure. Fortunately, this kind of hair loss usually is temporary. Typically, the hair grows back once the body adjusts, the disease is treated, or the medicine is stopped.

* thyroid gland: (THY-roid GLAND) is located in the lower part of the front of the neck. The thyroid produces hormones that regulate the body’s metabolism (me-TAB-o-LlZ-um), the processes the body uses to produce energy to grow, and to maintain body tissues.

* fungus: (FUN-gus) is any organism belonging to the kingdom Fungi (FUN-ji), which includes mushrooms, yeasts, and molds.

* chemotherapy: (KEE-mo-THER-a-pee) is the treatment of cancer with powerful drugs that kill cancer cells.

* depression: (de-PRESH-un) is a mental state characterized by feelings of sadness, despair, and discouragement.

Trichotillomania

Trichotillomania (trik-o-til-o-MAY-nee-a) is a psychological* disorder in which people pull out their own hair, leading to noticeable hair loss. The most commonly affected spots are the scalp, eyebrows, and eyelashes. This nervous habit may be a reaction to emotional stress or anxiety. It often begins in childhood, although it occurs in adults, too. The hair grows back once the hair pulling is stopped.

* psychological: (SI-ko-LOJ-i-kal) refers to mental processes, including thoughts, feelings, and emotions

Poor diet

When people do not get enough protein from their diet, the body may try to save protein by shifting hairs from the growing stage to the resting stage. As a result, a large number of hairs may fall out 2 to 3 months later, when the resting stage ends. Lack of iron also can lead to hair loss. Eating a healthy diet or taking iron pills can prevent or reverse this problem.

Improper hair care

Chemicals, such as dyes, bleaches, straighteners, and permanents, can damage the hair if used too often or left on too long. Even shampooing, brushing, and combing can harm the hair if done too roughly. Hairstyles that pull the hair, such as tight ponytails and braids, also put a lot of stress on it. Mistreating the hair in any of these ways can lead to temporary hair loss.

Hair-Raising Facts

Natural blondes have about 140,000 hairs on their head, on average. Brunettes have about 105,000 hairs, and redheads have about 90,000 hairs.
At any given time, about 90 percent of the hairs on a person’s head are growing. About 10 percent of the hairs are resting, getting ready to fall out.

How Is the Cause of Hair Loss Identified?

People who experience sudden, fast, or unusual hair loss should see a physician, who can identify the cause. In some cases, doctors may decide that the baldness is simply due to aging. In other cases, doctors may check the scalp and take samples from it to look for signs of disease. In addition, doctors may pluck several hairs from one spot on the head. These hairs then are examined under a microscope to see whether they are in the growing or resting stage. The percentage of hairs in each stage can provide another clue to the cause of the hair loss.

How Is Baldness Treated?

Hair loss due to alopecia areata usually clears up on its own with time. In the meantime, the condition sometimes is treated with corticosteroid* medicines that are rubbed onto the skin or taken by mouth or in a shot.

* corticosteroid: (KOR-ti-ko-STER-oid) is one of several medications that are prescribed to reduce inflammation and sometimes to suppress the body’s immune response.

Common baldness due to aging does not need treatment for medical reasons. However, some people seek help, because they are concerned about the way they look. There are several major treatment options.

Hairstyles, wigs, and hair additions

Simply getting the right haircut and styling the hair in a flattering way can make a big difference with thinning hair or scattered hair loss. For more widespread hair loss, wigs are an easy solution. Several kinds of partial wigs, known as hair additions, are available as well. They can be attached to the remaining hair or anchored to the scalp with special glues or fasteners.

Medication

Two medications are now approved in the United States for regrowing lost hair or preventing further hair loss: minoxidil (mi-NOK-si-dil) and finasteride (fi-NAS-ter-ide). Minoxidil (Rogaine) can be bought without a prescription. It is a liquid that is rubbed onto the scalp. Only about a quarter of men and a fifth of women who use regular-strength minoxidil regrow a significant amount of hair, and it may take several months before these results are noticeable. Any new hair that grows often is thinner and lighter in color than the original hair. Also, any hair growth that occurs will cease once the treatment is stopped.

Finasteride (Propecia) is a second drug, which is sold by prescription. It is taken in pill form. This drug is marketed only for men, because it has not been shown to work in women, and it can cause birth defects if used by pregnant women. More than four out of five men who use finasteride have a slowing of their hair loss, and more than three out of five may have some hair regrowth. As with minoxidil, though, it can take months to see these effects.

Surgery

Hair transplantation (trans-plan-TAY-shun) surgery is a lasting but expensive solution to hair loss. People who might benefit from this kind of surgery include men and some women with common baldness. The surgery also may help people who have lost some hair as a result of burns to or scars on the scalp, eyebrows, or eyelashes. The operation involves cutting tiny plugs of hair-bearing scalp from parts of the head where hair still grows, and then reattaching the plugs to bald parts of the head. No new hair is added. Existing hair simply is moved from one spot to another. Since hundreds or even thousands of the tiny plugs must be moved to get good results, the procedure usually is done in several surgery sessions that are months apart. Sometimes, a larger flap of skin is moved instead of many tiny plugs.

A Hairy Situation

Some people worry about having too little hair. Others worry about having too much. Hirsutism (HIR-soot-iz-uhm) is the medical term for excessive hair growth on the body and face, especially in women. Many women, particularly those of southern European and Middle Eastern descent, develop quite a bit of body and facial hair when they reach puberty. This is perfectly normal. In both women and men, the amount of body and facial hair often increases slowly with age. There is nothing abnormal or unhealthy about this, either.

If a person does not like the way the hair looks, it can be bleached or removed in a variety of ways. However, sometimes there is an increase in the growth of coarse, dark facial and body hair over a period of weeks or months. This can be a sign of a medical problem in which the level of androgens in the blood is abnormally high, as in certain disorders of the ovaries and adrenal glands.

Some medicines, such as steroids and certain blood pressure drugs, also may cause the growth of body and facial hair. In addition, anorexia nervosa (AN-o-REK-se-a ner-VO-sa), an eating disorder that involves self-starvation and often occurs in teenage girls, may cause an increase in fine body hair.

Scalp reduction surgery is another procedure, which may be combined with hair transplantation. It involves removing a bald area of scalp from the top of the head, and then pulling the hair-bearing scalp forward to cover the area.

Coping with Hair Loss

Hair loss can be upsetting, even when it is temporary. Hairstyles, wigs, hair additions, hats, and bandannas can help hide hair loss if it makes a person uncomfortable. For many people, hair loss simply does not matter. Others wear their baldness with pride. Many even shave any remaining hair if the hair loss is patchy. Often, it is just a matter of style.

See also

Cancer

Dietary Deficiencies

Fungal Infections

Ringworm

Resources

American Hair Loss Council, 401 N. Michigan Avenue, Chicago, IL 60611. This nonprofit group provides information about hair loss on its website. Telephone 312-321-5128 http://www.ahlc.org

American Society of Plastic and Reconstructive Surgeons, 444 E. Algonquin Road, Arlington Heights, IL 60005-4664. This organization for surgeons provides information about hair replacement surgery on its website. Telephone 847-228-9900 http://www.plasticsurgery.org

National Alopecia Areata Foundation, P.O. Box 150760, San Rafael, CA 94915-0760. This nonprofit group provides information about alopecia areata. Telephone 415-456-4644 http://www.alopeciaareata.com

Complete Human Diseases and Conditions

Hair Loss

views updated May 09 2018

Hair loss

Definition

Hair loss, or alopecia, is total or partial baldness caused by hormonal changes or physical or mental stress .

Description

Hair loss occurs for many reasons. Some causes, such as hormonal changes, are considered natural, while others signal serious health problems. Some conditions are confined to the scalp, while others reflect disease processes throughout the body.

Causes & symptoms

Androgenetic alopecia occurs in both men and women, and is considered normal in adult males. Also known as male pattern baldness, it is easily recognized by the distribution of hair loss over the top and front of the head (leaving a horseshoe pattern of hair) and by the healthy condition of the scalp. Women with androgenetic alopecia experience hair thinning, particularly over the top of the scalp. The disorder is thought to be caused by a genetic predisposition that triggers the production of certain enzymes that convert testosterone into the hormone dihydrotestosterone (DHT). DHT is known to shrink hair follicles, and can cause partial or complete hair loss.

Alopecia areata and alopecia circumscripta refer to hair loss conditions that can be patchy or extend to complete baldness. The exact cause of alopecia areata is unknown, but it is thought to be triggered by an immune system disorder.

Oftentimes, conditions affecting the skin of the scalp will result in hair loss. The first clue to the specific cause is the pattern of hair loss, whether it be complete baldness (alopecia capitis totalis ), patchy bald spots, thinning, or hair loss confined to certain areas. Also a factor is the condition of the hair and the scalp beneath it. Sometimes only the hair is affected; sometimes the skin is visibly diseased as well.

Fungal infections of the scalp usually cause patchy hair loss. The fungus, similar to the ones that cause athlete's foot and ringworm, often glows under ultraviolet light.

Complete hair loss is a common result of cancer chemotherapy, due to the toxicity of the drugs used. Placing a tourniquet around the skull just above the ears during the intravenous infusion of the drugs may reduce or eliminate hair loss by preventing the drugs from reaching the scalp. However, this technique may not be recommended in the treatment of certain types of cancer. An investigational topical gel that may prevent chemotherapy-related hair loss, known as GW 8510, was in clinical trials as of April 2000.

Systemic diseases often affect hair growth either selectively or by altering the skin of the scalp. One example is thyroid disorders. Hyperthyroidism (too much thyroid hormone) causes hair to become thin and fine. Hypothyroidism (too little thyroid hormone) thickens both hair and skin. Several autoimmune diseases also affect the skin and potentially the hair, notably lupus erythematosus.

Hair loss can also be caused by trichotillomania, a mental disorder or compulsion that causes a person to pull out his/her own hair. In some individuals severe mental or physical stress can cause hair loss, including major surgery or illness, significant life changes (i.e., divorce, death of a loved one), and drastic dietary changes. This type of hair loss is called Telogen effluvium, and is the second most common type of hair loss.

Diagnosis

Dermatologists are skilled in diagnosis by sight alone. For more obscure diseases, they may have to resort to a skin biopsy, removing a tiny bit of skin using a local anesthetic so that it can be examined under a microscope. Systemic diseases will require a complete

evaluation by a physician, including specific tests to identify and characterize the problem.

Treatment

Traditional Chinese medicine (TCM) has a particular understanding of baldness that is different from the allopathic view. TCM recommends foods to eat and others to avoid, herbs to treat hair loss, and special hair massage. One Chinese approach is to first understand where there is weak energy in the body and to strengthen the qi (chi) of those organ systems. Treatment is not a one-shot approach but a well-rounded response.

Vitamins B₆ and biotin are thought to advocate healthy hair growth, as are the minerals zinc, copper , and silica . Fifty milligrams of silica a day is thought to encourage hair growth in young men with alopecia. The herb horsetail (Equisetum arvense ) contains silica, and can be taken as an infusion, or tea. Copper and zinc have been shown to inhibit growth of the enzyme that causes DHT production. Iron supplements may be useful in individuals whose hair loss is caused by anemia or an inadequate intake of dietary iron.

The herbal remedies saw palmetto (Serenoa repens ) and pygeum (Pygeum africanum ) may be prescribed by an herbalist, naturopath, or holistic healthcare professional to stop or slow hair loss. Saw palmetto is thought to stop DHT production, and pygeum influences testosterone production. Both can be taken orally as a dietary supplement. The Chinese herb He Shou Wun (Polygonum multiflorum ) can be taken orally or applied as a topical formula.

For hair loss caused by trichotillomania (hair pulling), behavioral therapy may be a useful treatment program. If the hair pulling or hair loss itself is triggered by stress, there are a number of stress reduction therapies that can promote relaxation , including aromatherapy , muscle relaxation exercises, yoga, guided imagery , and biofeedback .

Allopathic treatment

Successful treatment of underlying causes is most likely to restore hair growth, be it the completion of chemotherapy, effective cure of a scalp fungus, or control of a systemic disease. Drugs such as minoxidil (Rogaine) and finasteride (Propecia, Proscar) promote hair growth in a significant minority of patients, especially those with male pattern baldness and alopecia areata. When used continuously for long periods of time, minoxidil produces satisfactory results in about one-quarter of patients with androgenic alopecia and as many as half the patients with alopecia areata. Both drugs have so far proved to be quite safe when used for this purpose. Side effects of Rogaine include some dryness and irritation of the scalp. Reported side effects of Propecia include infrequent cases of diminished sexual drive and impotence . Propecia is not approved for women because it can cause birth defects.

In 2001, a study was made of immunotherapy with diphencyprone to treat alopecia areata. A lag of three months from start of therapy to development of noticeable hair growth occurred. Researchers noted that the extent of the disease prior to therapy and age at time hair loss began affected treatment success. Patients who were older at onset of baldness had a better success rate than those who were younger. The study concluded that longterm therapy was required for effectiveness.

Over the past few decades there have appeared a multitude of hair replacement methods performed by both physicians and non-physicians. They range from simply weaving someone else's hair in with the remains of an individual's own hair to surgically transplanting thousands of hair follicles one at a time.

KEY TERMS

Autoimmune disease: —Certain diseases caused by the body's development of an immune reaction to its own tissues.

Expected results

The prognosis for individuals with hair loss varies with the cause. It is generally much easier to lose hair than to regrow it. Even when it returns, it is often thin and less attractive than the original crop.

Resources

BOOKS

American Society of Health-System Pharmacists Inc. American Hospital Formulary Service Drug Information. Bethesda, MD: American Society of Health-System Pharmacists Inc., 1998.

Bennett, J. Claude, and Fred Plum, eds. Cecil Textbook of Medicine. Philadelphia: W. B. Saunders, 1999.

PERIODICALS

Amichai, B., M. H. Grunwald, and R. Sobel. "5 Alpha-reductase Inhibitors—A New Hope in Dermatology?" International Journal of Dermatology (March 1997): 182–4.

Lewis, Eric J., et al. "Some Common—and Uncommon—Causes of Hair Loss." Patient Care (December 15, 1997): 50.

Watson, Fiona. "Dermatologists Must Sift Through Alternative Tx." Dermatology Times (November 1997): 5.

Wiseman, Marni C. "Protective Model for Immunotherapy of Alopecia Areata with Diphencyprone." JAMA, The Journal of the American Medical Association (November 21, 2001): 2384.

Paula Ford-Martin

Teresa G. Odle

Gale Encyclopedia of Alternative Medicine Ford-Martin, Paula; Odle, Teresa