There are more than 70 different sleep disorders that are generally classified into one of three categories:

• lack of sleep (e.g., insomnia),
• disturbed sleep (e.g., sleep apnea, REM sleep behavior disorder, restless leg syndrome and periodic limb movement disorder), and
• excessive sleep (e.g., narcolepsy).

In most cases, sleep disorders can be easily managed once they are properly diagnosed. Insomnia is the most common sleep disorder. It occurs more often in women and in the elderly.

Falling asleep and waking up are controlled by various chemical changes in the brain and in the blood. Foods and medicines that alter the balance of these chemicals also affect how well we sleep. Caffeine, for example, can cause insomnia (lack of sleep). Antidepressants can cause a loss of REM (rapid eye movement) sleep, as can smoking and alcohol. Smoking and alcohol also can result in a loss of deep sleep. Both REM and deep sleep are essential parts of the normal sleep cycle.

As with other neurological disorders, an accurate medical history is an essential component of a sleep disorder diagnosis. People with sleep disorders should keep a daily diary of activities and sleep-both when they try to go to sleep and when they actually do sleep. Behavior during sleep (e.g., snoring), and alcohol, tobacco, and other drug use should be reported to the physician.

A polysomnogram is a sleep study that involves using electroencephalography (EEG) to monitor the brain and muscle activity, heart rhythm, and breathing during sleep. Patients are usually tested in a sleep lab, or they are given portable equipment to take home. The EEG monitors the various stages of sleep, which is interpreted by the clinician. For example, the EEG shows the degree of muscle activity during the various NREM and REM sleep stages. This information may provide clues about the type and cause of the sleep disorder.

In people with suspected obstructive sleep apnea (OSA), overnight oximetry (measuring the oxygen saturation in the blood) may be performed to determine the oxygen level duriIn people with suspected narcolepsy, there are various tests that can be performed. The multiple sleep latency test (MSLT), for example, measures the time it takes for REM sleep to occur in patients who fall asleep suddenly and repeatedly. In people with narcolepsy, REM occurs immediately.

Treatment

Treatment for sleep disorders depends on the cause and may include non-medication therapies (behavioral therapy, use of breathing machines and others) as well as various medications (prescriptions medications and/or natural supplements). All treatment options will be determined by your doctor and discussed with you in detail.