Snoring

Definition

Snoring is a sound generated during sleep by vibration of loose tissue in the upper airway.

Description

Snoring is one symptom of a group of disorders known as sleep disordered breathing. It occurs when the soft palate, uvula, tongue, tonsils, and/or muscles in the back of the throat rub against each other and generate a vibrating sound during sleep. Twenty percent of all adults are chronic snorers, and 45% of normal adults snore occasionally. As people grow older, their chance of snoring increases. Approximately half of all individuals over 60 snore regularly.

In some cases, snoring is a symptom of a more serious disorder called obstructed sleep apnea (OSA). OSA occurs when part of the airway is closed off (usually at the back of the throat) while a person is trying to inhale during sleep, and breathing stops for more than 10 seconds before resuming again. These breathless episodes can occur as many as several hundred times a night.

People with OSA almost always snore heavily, because the same narrowing of the airway that causes snoring can also cause OSA. Snoring may actually attribute to OSA as well, because the vibration of the throat tissues which occurs in snoring can cause the tissue to swell.

Snoring is associated with physical problems as well as social stress. People who do not suffer from OSA may be diagnosed with socially unacceptable snoring (SUS), which refers to snoring that is loud enough to prevent the sleeper's bed partner or roommate from sleeping. SUS is a factor in the breakup of some marriages and other long-term relationships. Moreover, a study published in 2002 indicates that people who snore are at increased risk of developing type 2 diabetes. Snoring appears to be a risk factor that is independent of body weight or a family history of diabetes.

Causes and symptoms

There are several major causes of snoring, including:

• Excessively relaxed throat muscles. Alcohol, drugs, and sedatives can cause the throat muscles to become lax, and/or the tongue to pull back into the airway.
• Large uvula. The piece of tissue that hangs from the back of the throat is called the uvula. Individuals with a large or longer than average uvula can suffer from snoring when the uvula vibrates in the airway.
• Large tonsils and/or adenoids. The tonsils (tissue at the back of either side of the throat) can also vibrate if they are larger than normal, as can the adenoids.
• Excessive weight. Overweight people are more likely to snore. This is frequently caused by the extra throat and neck tissue they are carrying around.
• Nasal congestion. Colds and allergies can plug the nose, creating a vacuum in the throat that results in snoring as airflow increases.
• Cysts and tumors. Cysts and/or tumors of the throat can trigger snoring.
• Structural problems of the nose. A deviated septum or other nasal problems can also cause snoring.

Diagnosis

A patient interview, and possibly an interview with the patient's spouse or anyone else in the household who has witnessed the snoring, is usually enough for a diagnosis of snoring. A medical history that includes questions about alcohol or tranquilizer use; past ear, nose, and throat problems; and the pattern and degree of snoring will be completed, and a physical exam will be performed to determine the cause of the problem. This will typically include examination of the throat to look for narrowing, obstruction, or malformations. If the snoring is suspected to be a symptom of a more serious disorder such as obstructive sleep apnea, the patient will require further testing. This testing is called a polysomnography study, and is conducted during an overnight stay in a specialized sleep laboratory. The polysomnography study include measurements of heart rate, airflow at the mouth and nose, respiratory effort, sleep stage (light sleep, deep sleep, dream sleep, etc.), and oxygen level in the blood.

In some cases the patient may be referred to a dentist or orthodontist for evaluation of the jaw structure and dentition.

In addition, the patient may be examined by sleep endoscopy. In this procedure, the patient is given a medication (midazolam) to induce sleep. His or her throat and nasal passages are then examined with a flexible laryngoscope. In many cases, sleep endoscopy reveals obstructions that are not apparent during a standard physical examination of the throat. Many patients are found to have obstructions at more than one level in their breathing passages.

Treatment

Several surgical procedures are available for treating chronic snoring. These include:

• Uvulopalathopharyngoplasty (UPPP), a surgical procedure which involves removing excess throat tissues (e.g., tonsils, parts of the soft palate) to expand the airway.
• Laser-assisted uvulopalatoplasty (LAUP) uses a surgical laser to remove part of the uvula and palate.
• Palatal stiffening is a minimally-invasive surgical technique where a laser or a cauterizer is used to produce scar tissue in the soft palate in order to stop the vibrations that produce snoring.
• Radiofrequency ablation is another technique which uses scarring to shrink the uvula and/or soft palate. A needle electrode is used to shrink and scar the mouth and throat tissues.

Alternative treatment

There are a number of remedies for snoring, but few are proven clinically effective. Popular treatments include:

• Mechanical devices. Many splints, braces, and other devices are available which reposition the nose, jaw, and/or mouth in order to clear the airways. Other devices are designed to wake an individual when snoring occurs. Patients should consult a dentist or orthodontist about these devices, as most require custom fitting. In addition, persons with certain types of gum disease or dental problems should not be fitted with oral appliances to stop snoring.
• Nasal strips. Nasal strips that attach like an adhesive bandage to the bridge of the nose are available at most drugstores, and can help stop snoring in some individuals by opening the nasal passages.

• Continuous positive airway pressure (CPAP). Some chronic snorers find relief by sleeping with a nasal mask which provides air pressure to the throat.
• Decongestants. Snoring caused by nasal congestion may be successfully treated with decongestants. Some effective herbal remedies that clear the nasal passages include golden rod (Solidago virgauria ) and golden seal (Hydrastis canadensis ). Steam inhalation of essential oils of eucalyptus blue gum (Eucalyptus globulus ) or peppermint (Mentha x piperata ) can also relieve congestion.
• Weight loss. Snoring thought to be caused by excessive weight may be curtailed by a sensible weight loss and exercise program.
• Sleep position. Snoring usually worsens when an individual sleeps on his or her back, so sleeping on one's side may alleviate the problem. Those who have difficulty staying in a side sleeping position may find sleeping with pillows behind them helps them maintain the position longer. Other devices include a new vest designed to prevent the sleeper from lying on his or her back.
• Bed adjustments. For some people, raising the head of the bed solves their snoring problem. A slight incline can prevent the tongue from retracting into the back of the throat. Bricks, wooden blocks, or specially designed wedges can be used to elevate the head of the bed approximately 4-l6 in (10-41 cm).

Alternative treatments that have been reported to be effective for patients whose snoring is caused by colds or allergies include acupuncture, homeopathy, and aromatherapy treatments. Aromatherapy treatments for snoring typically make use of marjoram oil, which is thought to be particularly effective in clearing the nasal passages.

Prevention

Adults with a history of snoring may be able to prevent snoring episodes with the following measures:

• avoid alcohol and sedatives before bedtime
• remove allergens from the bedroom
• use a decongestant before bed
• sleep on the side, not the back

KEY TERMS

Ablation— The removal of abnormal tissue growths by surgery.

Cauterize— To seal tissue or blood vessels using a heat or electrical source.

Continuous positive airway pressure (CPAP)— A ventilation device that blows a gentle stream of air into the nose during sleep to keep the airway open.

Deviated septum— A hole or perforation in the septum, the wall that divides the two nasal cavities.

Endoscope— A slender optical instrument that allows a doctor to examine the inside of the throat or other hollow organ. Sleep endoscopy is a technique that allows the doctor to detect previously unsuspected obstructions in the patient's nose and throat.

Obstructive sleep apnea (OSA)— A potentially life-threatening condition characterized by episodes of breathing cessation during sleep alternating with snoring or disordered breathing. The low levels of oxygen in the blood of patients with OSA may eventually cause heart problems or stroke.

Polysomnography— A technique for diagnosing sleep disorders with the use of a machine that records the pulse, breathing rate and other variables while the patient sleeps.

Soft palate— The structure at the roof of the mouth that separates the mouth and the pharynx.

Resources

BOOKS

Beers, Mark H., MD, and Robert Berkow, MD., editors. "Disorders of the Oral Region." Section 9, Chapter 105 In The Merck Manual of Diagnosis and Therapy. Whitehouse Station, NJ: Merck Research Laboratories, 2004.

Beers, Mark H., MD, and Robert Berkow, MD., editors. "Sleep Disorders." Section 14, Chapter 173 In The Merck Manual of Diagnosis and Therapy. Whitehouse Station, NJ: Merck Research Laboratories, 2004.

Pelletier, Kenneth R., MD. The Best Alternative Medicine, Part I, Chapter 5, "Acupuncture," and Chapter 8, "Homeopathy." New York: Simon & Schuster, 2002.

PERIODICALS

Al-Delaimy, W. K., J. E. Manson, W. C. Willett, et al. "Snoring as a Risk Factor for Type II Diabetes Mellitus: A Prospective Study." American Journal of Epidemiology 155 (March 1, 2002): 394-395.

Ayappa, I., and D. M. Rapoport. "The Upper Airway in Sleep: Physiology of the Pharynx." Sleep Medicine Reviews 7 (February 2003): 3-7.

Blumen, M. B., S. Dahan, I. Wagner, et al. "Radiofrequency Versus LAUP for the Treatment of Snoring." Otolaryngology and Head and Neck Surgery 126 (January 2002): 67-73.

Ellis, S. G., N. W. Craik, R. F. Deans, and C. D. Hanning. "Dental Appliances for Snoring and Obstructive Sleep Apnoea: Construction Aspects for General Dental Practitioners." Dental Update 30 (January-February 2003): 16-22, 24-26.

Hassid, S., A. H. Afrapoli, C. Decaesteker, and G. Choufani. "UPPP for Snoring: Long-Term Results and Patient Satisfaction." Acta Otorhinolaryngologica Belgica 56 (2002): 157-162.

Hessel, N. S., and N. de Vries. "Diagnostic Work-Up of Socially Unacceptable Snoring. II. Sleep Endoscopy." European Archives of Otorhinolaryngology 259 (March 2002): 158-161.

Maurer, J. T., B. A. Stuck, G. Hein, et al. "Treatment of Obstructive Sleep Apnea with a New Vest Preventing the Supine Position." [in German] Deutsche medizinische Wochenschrift 128 (January 17, 2003): 71-75.

Nakano, H., T. Ikeda, M. Hayashi, et al. "Effects of Body Position on Snoring in Apneic and Nonapneic Snorers." Sleep 26 (March 15, 2003): 169-172.

Remacle, M., E. Jouzdani, G. Lawson, and J. Jamart. "Laser-Assisted Surgery Addressing Snoring Long-Term Outcome Comparing CO₂ Laser vs. CO₂ Laser Combined with Diode Laser." Acta Otorhinolaryngologica Belgica 56 (2002): 177-182.

Stevenson, J. E. "Diagnosis of Sleep Apnea." Wisconsin Medical Journal 102 (2003): 25-27, 46.

Trotter, M. I., A. R. D'Souza, and D. W. Morgan. "Medium-Term Outcome of Palatal Surgery for Snoring Using the Somnus Unit." Journal of Laryngology and Otology 116 (February 2002): 116-118.

ORGANIZATIONS

American Academy of Otolaryngology, Head and Neck Surgery, Inc. One Prince Street, Alexandria, VA 22314-3357. (703) 836-4444. 〈http://www.entnet.org〉.

American Academy of Sleep Medicine (AASM). One Westbrook Corporate Center, Suite 920, Westchester, IL 60154. (708) 492-0930. 〈http://www.aasmnet.org〉.

American Dental Association. 211 East Chicago Avenue, Chicago, IL 60611. (312) 440-2500. 〈http://www.ada.org〉.

American Sleep Apnea Association. Wake-Up Call: The Wellness Letter for Snoring and Apnea. 1424 K Street NW, Suite 302, Washington, DC 20005. (202) 293-3650. 〈http://www.sleepapnea.org〉.

National Sleep Foundation. 1522 K Street, NW, Suite 500, Washington, DC 20005. 〈http://www.sleepfoundation.org〉.

OTHER

American Sleep Apnea Association (ASAA). Considering Surgery for Snoring? 〈http://www.sleepapnea.org/snoring.html〉.

National Heart, Lung, and Blood Institute (NHLBI). Facts About Sleep Apnea. NIH Publication No. 95-3798. [cited April 13, 2003]. 〈http://www.nhlbi.nih.gov/health/public/sleep/sleepapn.htm〉.

Snoring

Definition

Snoring is a sound generated during sleep by vibration of loose tissue in the upper airway.

Description

Snoring is one symptom of a group of disorders known as sleep-disordered breathing. It occurs when the soft palate, uvula, tongue, tonsils, and/or muscles in the back of the throat rub against each other and generate a vibrating sound during sleep. Twenty percent of all adults are chronic snorers, and 45% of normal adults snore occasionally. As people grow older, their chance of snoring increases. Approximately half of all individuals over 60 snore regularly.

In some cases, snoring is a symptom of a more serious disorder called obstructive sleep apnea (OSA). OSA occurs when part of the airway is closed off (usually at the back of the throat) while a person is trying to inhale during sleep, and breathing stops for more than 10 seconds before resuming again. These breathless episodes can occur as many as several hundred times a night.

People with OSA almost always snore heavily because the same narrowing of the airway that causes snoring can also cause OSA. Snoring may actually contribute to OSA as well, because the vibration of the throat tissues that occurs in snoring can cause the tissue to swell.

Snoring is associated with physical problems as well as social stress . People who do not suffer from OSA may be diagnosed with socially unacceptable snoring (SUS), which refers to snoring that is loud enough to prevent the sleeper's bed partner or roommate from sleeping. SUS is a factor in the breakup of some marriages and other long-term relationships. Moreover, a study published in 2002 indicates that people who snore are at increased risk of developing type 2 diabetes. Snoring appears to be a risk factor that is independent of body weight or a family history of diabetes.

Causes & symptoms

There are several major causes of snoring, including:

• Excessively relaxed throat muscles. Alcohol, drugs, and sedatives can cause the throat muscles to become lax, and/or the tongue to pull back into the airway.
• Large uvula. The piece of tissue that hangs from the back of the throat is called the uvula. Individuals with a large or longer than average uvula can suffer from snoring when the uvula vibrates in the airway.
• Large tonsils and/or adenoids. The tonsils (tissue at the back of either side of the throat) can also vibrate if they are larger than normal, as can the adenoids.
• Excessive weight. Overweight people are more likely to snore. Their snoring is frequently caused by the extra throat and neck tissue they are carrying around.
• Nasal congestion. Colds and allergies can plug the nose, creating a vacuum in the throat that results in snoring as airflow increases.
• Cysts and tumors. Cysts and/or tumors of the throat can trigger snoring.
• Structural problems of the nose. A deviated septum or other nasal problems can also cause snoring.

Diagnosis

A patient interview, and possibly an interview with the patient's spouse or anyone else in the household who has witnessed the snoring, is usually enough for a diagnosis of snoring. A medical history that includes questions about alcohol or tranquilizer use; past ear, nose, and throat problems; and the pattern and degree of snoring will be completed, and a physical examination will be performed to determine the cause of the problem. This will typically include examination of the throat to look for narrowing, obstruction, or malformations.

In some cases the patient may be referred to a dentist or orthodontist for evaluation of the jaw structure and dentition.

In addition, the patient may be examined by sleep endoscopy. In this procedure, the patient is given a medication (midazolam) to induce sleep. His or her throat and nasal passages are then examined with a flexible laryngoscope. In many cases, sleep endoscopy reveals obstructions that are not apparent during a standard physical examination of the throat. Many patients are found to have obstructions at more than one level in their breathing passages.

If the snoring is suspected to be a symptom of a more serious disorder such as obstructive sleep apnea, the patient will require further testing. This testing is called a polysomnography study, and is conducted during an overnight stay in a specialized sleep laboratory. The polysomnography study includes measurements of heart rate, airflow at the mouth and nose, respiratory effort, sleep stage (light sleep, deep sleep, dream sleep, etc.), and oxygen level in the blood.

Treatment

There are a number of remedies for snoring, but few are proven clinically effective. Popular treatments include:

• Mechanical devices. Many splints, braces, and other devices are available to reposition the nose, jaw, and/or mouth in order to clear the airways. Other devices are designed to wake an individual when snoring occurs. Patients should consult a dentist or orthodontist about these devices, as most require custom fitting. In addition, persons with certain types of gum disease or dental problems should not be fitted with oral appliances to stop snoring.
• Nasal strips. Nasal strips that attach like an adhesive bandage to the bridge of the nose are available at most drugstores, and can help stop snoring in some individuals by opening the nasal passages.
• Continuous positive airway pressure (CPAP). Some chronic snorers find relief by sleeping with a nasal mask that provides air pressure to the throat.
• Decongestants. Snoring caused by nasal congestion may be successfully treated with decongestants. Some effective herbal remedies that clear the nasal passages include golden rod (Solidago virgauria ) and golden seal (Hydrastis canadensis ). Steam inhalation of essential oils of eucalyptus blue gum (Eucalyptus globulus ) or peppermint (Mentha x piperata ) can also relieve congestion.
• Weight loss. Snoring thought to be caused by excessive weight may be curtailed by a sensible weight loss and exercise program.
• Sleep position. Snoring usually worsens when an individual sleeps on his or her back, so sleeping on one's side may alleviate the problem. Those who have difficulty staying in a side sleeping position may find sleeping with pillows behind them helps them maintain the position longer. Other devices include a new vest designed to prevent the sleeper from lying on his or her back.
• Bed adjustments. For some people, raising the head of the bed solves their snoring problem. A slight incline can prevent the tongue from retracting into the back of the throat. Bricks, wooden blocks, or specially designed wedges can be used to elevate the head of the bed approximately 4–6 in.

Alternative treatments that have been reported to be effective for patients whose snoring is caused by colds or allergies include acupuncture, homeopathy , and aromatherapy treatments. Aromatherapy treatments for snoring typically make use of marjoram oil, which is thought to be particularly effective in clearing the nasal passages.

Allopathic treatment

Several surgical procedures are available for treating chronic snoring. These include:

• Uvulopalatopharyngoplasty (UPPP), a surgical procedure that involves removing excess throat tissues (e.g., tonsils, parts of the soft palate) to expand the airway. The success rate of UPPP is about 53% after five years. The success of the surgery is related to the patient's body mass before the operation.
• Laser-assisted uvulopalatoplasty (LAUP) uses a surgical laser to remove part of the uvula and palate. Its chief drawback is a period of discomfort that lasts for about a week following surgery.
• Palatal stiffening is a minimally invasive surgical technique in which a laser or cauterizer is used to produce scar tissue in the soft palate in order to stop the vibrations that produce snoring.
• Radiofrequency ablation is another technique that uses scarring to shrink the uvula and/or soft palate. A needle electrode is used to shrink and scar the mouth and throat tissues. Like other surgical treatments for snoring, radiofrequency ablation has a relapse rate over the long term. One of its advantages, however, is that it is less painful than other surgical treatments.

Prevention

Adults with a history of snoring may be able to prevent snoring episodes with the following measures:

• Avoid alcohol and sedatives before bedtime.
• Remove allergens from the bedroom.
• Use a decongestant before bed.
• Sleep on the side of the body, not the back.

Resources

BOOKS

"Disorders of the Oral Region." Section 9, Chapter 105 in The Merck Manual of Diagnosis and Therapy, edited by Mark H. Beers, MD, and Robert Berkow, MD. Whitehouse Station, NJ: Merck Research Laboratories, 1999.

Pascualy, Ralph A. and Sally Warren Soest. Snoring and Sleep Apnea: Personal and Family Guide to Diagnosis and Treatment. New York: Demos Medical Publishing, 1996.

Pelletier, Kenneth R., MD. The Best Alternative Medicine, Part I, Chapter 5, "Acupuncture," and Chapter 8, "Homeopathy." New York: Simon & Schuster, 2002.

Price, Shirley. Practical Aromatherapy, 3rd ed. London, UK: Thorsons, 1994.

"Sleep Disorders." Section 14, Chapter 173 in The Merck Manual of Diagnosis and Therapy, edited by Mark H. Beers, MD, and Robert Berkow, MD. Whitehouse Station, NJ: Merck Research Laboratories, 1999.

PERIODICALS

Al-Delaimy, W. K., J. E. Manson, W. C. Willett, et al. "Snoring as a Risk Factor for Type II Diabetes Mellitus: A Prospective Study." American Journal of Epidemiology 155 (March 1, 2002): 394-395.

Ayappa, I., and D. M. Rapoport. "The Upper Airway in Sleep: Physiology of the Pharynx." Sleep Medicine Reviews 7 (February 2003): 3–7.

Blumen, M. B., S. Dahan, I. Wagner, et al. "Radiofrequency Versus LAUP for the Treatment of Snoring." Otolaryngology and Head and Neck Surgery 126 (January 2002): 67-73.

Ellis, S. G., N. W. Craik, R. F. Deans, and C. D. Hanning. "Dental Appliances for Snoring and Obstructive Sleep Apnoea: Construction Aspects for General Dental Practitioners." Dental Update 30 (January-February 2003): 16–22, 24–26.

Hassid, S., A. H. Afrapoli, C. Decaesteker, and G. Choufani. "UPPP for Snoring: Long-Term Results and Patient Satisfaction." Acta Otorhinolaryngologica Belgica 56 (2002): 157-162.

Hessel, N. S., and N. de Vries. "Diagnostic Work-Up of Socially Unacceptable Snoring. II. Sleep Endoscopy." European Archives of Otorhinolaryngology 259 (March 2002): 158-161.

Maurer, J. T., B. A. Stuck, G. Hein, et al. "Treatment of Obstructive Sleep Apnea with a New Vest Preventing the Supine Position." [in German] Deutsche medizinische Wochenschrift 128 (January 17, 2003): 71–75.

Nakano, H., T. Ikeda, M. Hayashi, et al. "Effects of Body Position on Snoring in Apneic and Nonapneic Snorers." Sleep 26 (March 15, 2003): 169–172.

Remacle, M., E. Jouzdani, G. Lawson, and J. Jamart. "Laser-Assisted Surgery Addressing Snoring Long-Term Outcome Comparing CO₂ Laser vs. CO₂ Laser Combined with Diode Laser." Acta Otorhinolaryngologica Belgica 56 (2002): 177-182.

Stevenson, J. E. "Diagnosis of Sleep Apnea." Wisconsin Medical Journal 102 (2003): 25–27, 46.

Trotter, M. I., A. R. D'Souza, and D. W. Morgan. "Medium-Term Outcome of Palatal Surgery for Snoring Using the Somnus Unit." Journal of Laryngology and Otology 116 (February 2002): 116-118.

ORGANIZATIONS

American Academy of Otolaryngology, Head and Neck Surgery, Inc. One Prince Street, Alexandria, VA 22314-3357. (703) 836-4444. <http://www.entnet.org>.

American Academy of Sleep Medicine (AASM). One West-brook Corporate Center, Suite 920, Westchester, IL 60154. (708) 492-0930. <http://www.aasmnet.org>.

American Dental Association. 211 East Chicago Avenue, Chicago, IL 60611. (312) 440-2500. <http://www.ada.org>.

American Sleep Apnea Association. Wake-Up Call: The Wellness Letter for Snoring and Apnea. 1424 K Street NW, Suite 302, Washington, DC 20005. (202) 293-3650. http://www.sleepapnea.org.

National Sleep Foundation. 1522 K Street, NW, Suite 500, Washington, DC 20005. http://www.sleepfoundation.org.

OTHER

American Sleep Apnea Association (ASAA). Considering Surgery for Snoring? <http://www.sleepapnea.org/snoring.html>.

National Heart, Lung, and Blood Institute (NHLBI). Facts About Sleep Apnea. NIH Publication No. 95-3798. <http://www.nhlbi.nih.gov/health/public/sleep/sleepapn.htm>.

Paula Ford-Martin

Rebecca J. Frey, PhD

snoring ‘Laugh and the world laughs with you, snore, and you snore alone’ — from Anthony Burgess's Inside Mr Enderby (1963). It is a misquote of the original ‘Laugh and the world laughs with you, weep, and you weep alone’, from Ella Wheeler Wilcox (1855–1919).

Snoring has been a source of material for music hall mirth and general humour for centuries. Its association with obesity and alcohol has offered further scope for the stand-up comedian. Until relatively recently snoring was not considered a significant problem, except by the long-suffering partner behind closed bedroom doors, and those musing on the possible evolutionary advantage of snoring — the most entertaining suggestion from the latter being that snoring is a signal during the dark hours to potential marauders that there are large men about, so attack at your peril!

All this has changed since about 1965, when it was first reported that the pharynx, more specifically the airway behind the tongue, could collapse repeatedly during sleep, thus recurrently asphyxiating the sufferer, over and over again, hundreds of times a night. This condition is generally called obstructive sleep apnoea. This incompetence of the pharynx and failure to remain adequately patent only occurs during sleep, when muscle tone is at its lowest. It is always accompanied by loud snoring, which develops when the pharyngeal walls are close enough together to vibrate, a half-way house to complete obstruction. This condition of obstructive sleep apnoea is not just a physiological curiosity, but has been shown to lead to profound sleep fragmentation and excessive sleepiness. More recently, this excessive sleepiness has been shown to increase substantially the risk of driving accidents.

Both snoring and sleep apnoea are common; about a quarter of men snore regularly and about 1% have sleep apnoea sufficient to cause some degree of excessive daytime sleepiness. Why should this be the case? To some extent the pharynx represents an area of ‘compromise engineering’. Because we must both eat and breathe through the pharynx, sometimes it has to be held open by muscles to allow air to pass unheeded, and sometimes it must collapse and propel food on its way into the oesophagus (gullet). Thus it is essentially a floppy tube, which requires muscle action to hold it open when required for breathing. The main factor that encourages narrowing and collapse is obesity, which crowds the pharyngeal airway and can overwhelm the dilator muscle action during sleep. For example, collar size is one of the best predictors of whether someone snores. In addition, if the pharynx is small to start with — for example if the lower face is relatively set back — or occupied by large tonsils, then it takes little further narrowing to obstruct airflow. It would have been so much better if nature had provided us with separate routes through which to eat and breathe!

Other factors that encourage snoring and sleep apnoea are the muscle relaxation brought about by alcohol, and a blocked nose (which encourages further collapse of the pharynx during inspiration).

What does all this mean to the health of the human body? There is little evidence that occasional light snoring does any harm at all. As the amount of obstruction in the pharynx gets more, and the snoring gets louder, then this indicates a compromised airway and increasingly obstructed breathing. This in turn produces poor, fragmented sleep and daytime sleepiness. Thus a snorer with daytime sleepiness should be encouraged to seek help. There is also increasing evidence that heavy snoring and sleep apnoea may contribute to a raised blood pressure, with secondary consequences such as stroke and heart attacks. However, this effect is likely to be small when compared with other known risk factors such as smoking.

The sound of snoring alone causes much misery to partners, and for this reason many remedies are peddled. Few have robust scientific support, although weight loss, alcohol reduction, and sleeping semi-propped up are usually the simplest first approaches. Small intra-oral devices worn in the mouth at night to hold the lower jaw forward are increasingly popular. Surgery should be viewed as a last resort for the desperate, as it is of only limited efficacy. At the more severe end of the spectrum, for obstructive sleep apnoea, nasal continuous positive airway pressure treatment is highly effective. This requires wearing, during sleep, a mask over the nose that gently pressurizes the upper airway and splints it open, preventing the narrowing and collapse. However, this is difficult to get used to, and is only tolerated by individuals suffering from incapacitating daytime sleepiness — which this treatment abolishes, leading to spectacular improvement in quality of life.

J. Stradling

snoring (snor-ing) n. noisy breathing while asleep due to vibration of the soft palate, uvula, pharyngeal walls, or epiglottis.