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A polysomnogram is a painless test that measures brain waves (EEG), eye movements (EOG), muscle activity from the chin and legs, and breathing. The breathing measurements include airflow from the nose and mouth, snoring (measured using a microphone taped to your neck) chest and abdominal movements and oxygen level (measured using a light that shines through the blood vessels in the finger).

The test determines sleep quality, sleep duration, leg movements during sleep, regularity of breathing during sleep and any unusual behaviors during sleep.

What to Expect                                  

When you arrive at the laboratory, you will watch a film that describes breathing problems during sleep and their treatment. Then the technician will escort you to a comfortable, private bedroom. The room is equipped with a television set with cable. You will be asked to change into sleeping clothes (shorts or sweat pants and a loose top are best). The technician will attach the sensors to your head and body, and at approximately 10:30 p.m. to 11:30 p.m., you will be asked to go to sleep and the test will begin.

What to do Prior to the Polysomnogram

  • Avoid caffeine after noon on the day of the test. This includes colas and some other soft drinks, coffee, tea and chocolate. If you drink alcohol on a regular basis (every day or almost every day), please have your usual amount on the day of the test. If you drink infrequently, (once a week or less) please do not have alcohol on the day of the test.
  • Wash hair with shampoo to remove all hair products and then dry hair. Some products can interfere with the electrode contact with your scalp.
  • Remove nail polish from one index finger, either hand, to allow for the placement of an oxygen sensor.
  • Try not to nap on the day of the test.
  • Bring any medications that you usually take at bedtime or in the morning, unless you have specific instructions from your doctor not to do so. Also, bring a list of all the medications you have taken in the two weeks prior to the test.
  • Bring anything that might make your night in the laboratory more comfortable (pillows, earplugs, masks or stuffed animals).