Restless leg syndrome (RLS) and periodic limb movement disorder (PLMD) are common sleep disorders, especially in the elderly. RLS is a genetic disorder resulting in prickly or tingling sensations in the leg that cause patients to want to move their legs. It often results in insomnia. PLMD causes jerking in the legs or arms that occurs frequently during resting or sleeping. Jerking may occur as many as 3 times in a minute and each jerk can wake the patient.

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.

These disorders may be treated using medication.