A polysomnography test may be done
to check the patterns of brain waves and other physical functions during sleep. The
is often done in a sleep clinic overnight to look at the body's activity during sleep.
The test measures heart rate, respiration, muscle activity, blood pressure, brain
activity, and eye movement. The test can show whether you are asleep and whether you
have any problems in the sleep pattern. This test often includes an electroencephalogram
(EEG), EOG, and EMG. The EEG measures brain activity.