Sleep disorders are any difficulties related to sleeping. They may include difficulty falling or staying asleep, falling asleep at inappropriate times, sleeping excessively or abnormal behaviors during sleep.

According to the National Center on Sleep Disorders Research, about 70 million Americans have a sleep problem. Among those, almost 60 percent have a chronic disorder. Sleep disorders affect people of all ages, although people over age 65 are more likely to experience sleep problems.

More than 100 sleep disorders have been identified. They may be divided into dyssomnias (e.g., insomnia, sleep apnea), parasomnias (e.g., night terrors, sleepwalking), sleep disorders associated with medical or psychiatric conditions and proposed sleep disorders (sleep problems for which there is insufficient information to establish them as distinct disorders).

Sleep disorders may be caused by a variety of factors. Medical conditions (e.g., asthma) or the use of certain medications (e.g., certain antidepressants) may affect sleep. In addition, lifestyle factors, such as working the night shift, may contribute to sleep disorders.

Signs and symptoms of sleep disorders may include difficulty falling asleep, waking up during the night and excessive daytime drowsiness.

Sleep disorders may take time to diagnose. A patient may first undergo a physical examination that includes a medical history and psychiatric history. If the cause of the sleep problem is not apparent, patients may be referred to a sleep center where sleep patterns are analyzed in depth.

Treatment of sleep disorders varies depending on the cause of the disorder. Treatment may include lifestyle changes (such as avoiding caffeine and alcohol), losing weight, exercising and medications. Patients may also receive relaxation therapy and/or cognitive behavioral therapy (CBT). Left untreated, some sleep disorders can be life-threatening. Excessive daytime sleepiness can cause people to fall asleep at inappropriate times, such as while driving.