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A sleep study is a way of observing how your body responds during sleep, and thereby discovering what may be causing you not to sleep well. Sensor pads are placed at various points on your face, scalp and abdomen, to measure physical movement and electrical brain impulses that indicate if you are entering and alternating between the two stages of sleep (REM and non-REM). Common sleep disorders and problems can be diagnosed in this way, including sleep apnea, sleepwalking, insomnia, and narcolepsy, to name a few.

Sleep studies can be ordered by a physician to aid in the diagnosis and treatment of these disorders. Sleep studies are conducted in a sleep lab or sleep study center, which usually require an overnight stay in a comfortable bed or private room.

Types of Sleep Studies

If your doctor orders a sleep study, chances are it will be one of the following common studies:

  • Polysomnogram -  Measures and records brain activity, movement of the eyes, body muscles, chest and belly, oxygen and CO2 blood levels, heart rate and rhythm, breathing rate and rhythm, the flow of air through your mouth and nose, and snoring
  • Multiple sleep latency test (MSLT) - Measures and records whether you reach REM stage of sleep, and how long it takes you to fall asleep and enter REM stage
  • Maintenance of wakefulness test (MWT) - Measures and records whether you are able to stay awake during periods when you would normally be awake
  • Actigraphy - Test for patients when shift work sleep disorder is suspected. A device that looks similar to a watch is worn on your wrist, and measures movement when sleeping and awake