A polysomnogram is a procedure that records a variety of body functions during sleep, including eye movement, muscle activity, and electrical activity of the brain. This test is done as part of a series of sleep tests to diagnose sleep disorders, such as sleep apnea, and problems staying awake or sleeping.

Polysomnograms usually are done in a hospital sleep lab and are monitored by a trained sleep lab technician. Small metal discs called electrodes are attached to the person's head and body to record brain activity, eye movements, muscle movements, heart rhythm and rate, limb movements, and snoring. There is no pain or physical discomfort associated with these tests. Polysomnogram recording equipment and video monitors record the person's movements and activities during sleep. The technician is in a separate room monitoring the test.

Polysomnogram test results are generally available within 1 to 2 weeks.