It is estimated that 50-70 million Americans chronically suffer from sleep disorders, hindering daily living and adversely affecting health and well being. Sleep disorders and deprivation have also been associated with increased risk of heart disease, diabetes, hypertension, obesity, depression and stroke. Billions of dollars are spent each year on clinic appointments, diagnostic tests, prescriptions and over-the-counter medications. Indirect costs due to lost productivity and other factors are probably much greater. An estimated 20 percent of serious car accidents are caused by driver sleepiness.
Doctors have described more than 70 sleep disorders, most of which can be managed effectively once they are correctly diagnosed. The most common sleep disorders include insomnia, sleep apnea, restless legs syndrome, and narcolepsy.
Insomnia is the most commonly reported sleep disorder, with chronic insomnia, affecting 10-15 percent of adult Americans. It is defined by difficulty falling asleep, maintaining sleep, or by short-duration sleep, even when there is ample opportunity for a full night’s sleep. Other symptoms include daytime fatigue, irritability, lack of energy and difficulty concentrating. Insomnia can result from stress, jet lag, diet, or many other factors. Severe insomnia can affect job performance and well-being the next day.
The frequency of insomnia tends to increase with age and affects women about 1.5 times more frequently than men. It is often a major disabling symptom of an underlying medical or psychiatric disorder.
Mild insomnia often can be prevented or cured by practicing good sleep habits. More severe or chronic insomnia is best treated by behavioral therapies, sometimes with the addition of sleeping medications.
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. Obstructive sleep apnea, is usually associated with loud snoring (though not everyone who snores has this disorder). Sleep apnea also can occur if the neurons that control breathing malfunction during sleep, an individual stops initiating breathing during sleep; this is referred to as central sleep apnea, and forms of it can occur in medical disorders such as congestive heart failure, for example.
During an episode of obstructive apnea, efforts to inhale air create suction that collapses the windpipe. This blocks the airflow for 10 seconds to as much as a minute while the sleeping person attempts to breathe. When the blood oxygen level falls, the brain responds by waking the person enough to tighten the upper airway muscles and open the windpipe. The person may snort or gasp, then resume snoring as he/she falls back to sleep. 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 or a decline in mental functioning. It also is linked to high blood pressure, irregular heartbeats and an increased risk of heart attacks and stroke. Patients with severe, untreated sleep apnea are two to three times more likely to have automobile accidents than the general population. In some high-risk individuals, sleep apnea may even lead to sudden death from respiratory arrest during sleep, heart attacks or strokes.
While an estimated 18 million Americans have sleep apnea, few of them have had the problem diagnosed. Patients with the typical features of sleep apnea, such as loud snoring, obesity and excessive daytime sleepiness, should be referred to a sleep specialist for further evaluation and possible diagnostic testing.
If sleep apnea is diagnosed, several treatments are available. Mild sleep apnea frequently can be overcome through weight loss or by preventing the person from sleeping on his or her back. Other people may need special devices such as continuous positive air pressure (CPAP), oral appliances or surgery to correct the obstruction. People with sleep apnea should be cautious in taking sedatives or sleeping pills, or drinking alcohol before bed, which can prevent them from waking enough to breathe.
Restless Legs Syndrome
Restless legs syndrome (RLS), a familial disorder affecting roughly 6 million Americans, is emerging as one of the most common sleep disorders, especially among older people. RLS is characterized by unpleasant crawling, prickling, or tingling sensations in the legs and feet and an urge to move them for relief. 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.
Many RLS patients also have a disorder known as periodic limb movement disorder (PLMD), which causes repetitive jerking movements of the limbs, especially the legs. These movements occur every 20 to 40 seconds and cause repeated waking and severely fragmented sleep.
Narcolepsy affects an estimated 250,000 Americans. It is one of the most uncommon and unusual sleep disorders. 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 attacks 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 fall asleep or awaken, and disrupted nighttime sleep. The symptoms of narcolepsy typically appear during adolescence, though it often takes years to obtain a correct diagnosis. The disorder (or at least a predisposition to it) is usually hereditary, but it occasionally is linked to brain damage from a head injury or other neurological disease.
Once narcolepsy is diagnosed, stimulants, antidepressants or other drugs can help control the symptoms and prevent the embarrassing and dangerous effects of falling asleep at improper times. Naps at certain times of the day also may reduce the excessive daytime sleepiness.