During any given night, a person with sleep apnea may involuntarily stop breathing 20 to 30 times per hour. These pauses in breathing are usually accompanied by snoring, although not everyone who snores has sleep apnea. The snoring occurs because, although the person continues to try to breathe, air cannot flow easily in and out of the mouth. Choking also can occur.
During the pause in breathing, the person is unable to inhale oxygen and exhale carbon dioxide, resulting in increased levels of carbon dioxide in the blood. This increase in carbon dioxide alerts the brain to wake the person. Breathing often resumes with a loud snort or a gasp. The frequent arousal prevents the person from getting enough sleep and often causes early morning headaches and daytime drowsiness. Daytime concentration and performance suffer due to sleep deprivation.
Sleep apnea occurs in all age groups but is more common in men than in women. More than 12 million people in the United States are estimated to have the disorder. People most likely to have sleep apnea are those who snore loudly and also are overweight, have high blood pressure, or have a physical abnormality inside the nose or upper airway. The problem appears to run in families, suggesting a possible genetic cause.
To diagnose sleep apnea, doctors use two tests, performed either at a sleep center or at home. One test is polysomnography, which records various body functions—such as the electrical activity of the brain, eye movement, muscle activity, heart rate, and blood oxygen levels—during sleep. A test called the multiple sleep latency test measures how fast a person falls asleep. (It takes most people 10 to 20 minutes to fall asleep; people who habitually fall asleep in fewer than 5 minutes are likely to require treatment for a sleep disorder.)
Treatment for sleep apnea depends on the underlying cause. Lifestyle changes are enough to reverse the disorder in some people. Such changes may include avoiding the use of alcohol, tobacco, and sleeping pills, all of which can make the airway more likely to collapse during sleep. Overweight people can benefit from losing weight. People in whom sleep apnea occurs only when they sleep on their backs are advised to sleep on their sides. The most common treatment for the disorder is called continuous positive airway pressure, in which the person wears a mask over the nose during sleep so that pressure from an air blower can force air through the nasal passages. The process also helps prevent the airway from collapsing during sleep. Side effects may include nasal irritation and drying, facial skin irritation, sore eyes, headaches, and abdominal bloating. Dental appliances can reposition the lower jaw and tongue during sleep to reduce the risk of airway obstruction. Medications are generally not effective for treating sleep apnea.
Some people with sleep apnea undergo surgery to increase the size of their airways. Common surgical procedures include removal of the adenoids (tissue at the back of the nasal cavity that helps the body fight infection), tonsils, nasal polyps, or uvula and part of the soft palate. People with life-threatening sleep apnea may need a tracheostomy, in which a small hole is made in the windpipe and a tube is inserted through which air can flow directly into the lungs while the person sleeps.