A sleep study, or polysomnogram, is a 12-hour recording of sleep patterns and behaviors performed in order to determine what stages of sleep an individual achieves and whether any sleep-related abnormalities are present. The patient will be hooked up to a variety of sensors that will record brain waves, eye movements, body movements, heart rate and breathing patterns. Audiovisual recordings are also made, and the oxygen content of the blood is measured with a finger cuff.
During the sleep study, every attempt is made to allow for a normal night's sleep. Some people sleep better or worse when away from home, but in either case this will not affect the quality of the sleep study.