Sleep apnea is a disorder of interrupted breathing during sleep. It usually occurs in association with fat buildup or loss of muscle tone with aging. These changes allow the windpipe to collapse during breathing when muscles relax during sleep. This problem, called obstructive sleep apnea, is usually associated with loud snoring (though not everyone who snores has it).
During an episode of obstructive apnea, the person’s effort to inhale air creates suction that collapses the windpipe. This blocks the airflow for ten seconds to a minute while the sleeping person struggles to breathe. When the person’s blood oxygen level falls, the brain responds by awakening the person enough to tighten the upper airway muscles and open the windpipe. The person may snort or gasp, then resume snoring. This cycle may be repeated hundreds of times a night.
The frequent awakenings that sleep apnea patients experience leave them continually sleepy and may lead to personality changes such as irritability or depression. Sleep apnea also deprives the person of oxygen, which can lead to morning headaches, a loss of interest in sex or a decline in mental functioning. It is also linked to high blood pressure, irregular heartbeats and an increased risk of heart attacks and stroke.
Restless Legs Syndrome
Restless legs syndrome (RLS), a familial disorder causing unpleasant crawling, prickling or tingling sensations in the legs and feet and an urge to move them for relief, is emerging as one of the most common sleep disorders, especially among older people. This disorder, which affects as many as 12 million Americans, leads to constant leg movement during the day and insomnia at night. Severe RLS is most common in elderly people, though symptoms may develop at any age. In some cases, it may be linked to other conditions such as anemia, pregnancy or diabetes.
Narcolepsy affects an estimated 250,000 Americans. People with narcolepsy have frequent “sleep attacks” at various times of the day, even if they have had a normal amount of nighttime sleep. These last from several seconds to more than 30 minutes. People with narcolepsy also may experience cataplexy (loss of muscle control during emotional situations), hallucinations, temporary paralysis when they awaken and disrupted nighttime sleep. These symptoms seem to be features of REM sleep that appear during waking, which suggests that narcolepsy is a disorder of sleep regulation.
The symptoms of narcolepsy typically appear during adolescence, though it often takes years to obtain a correct diagnosis. The disorder is usually hereditary, but it is occasionally linked to brain damage from a head injury or neurological disease.
Almost everyone occasionally suffers from short-term insomnia. This problem can result from stress, jet lag, diet or many other factors. Insomnia almost always affects job performance and well-being the next day. About 60 million Americans a year have insomnia frequently or for extended periods of time, which leads to even more serious sleep deficits. Insomnia tends to increase with age and affects about 40 percent of women and 30 percent of men. It is often the major disabling symptom of an underlying medical disorder.