A sleep study helps doctors determine the cause of a sleep disorder. Some sleep studies take place at sleep centers while others take place at patients’ homes. Learn what happens during a sleep study at a sleep study center.
Overnight Studies at Sleep Centers
If your symptoms indicate sleep apnea or another sleep disorder, you may need to stay overnight at a sleep study center for a nocturnal polysomnogram. You arrive at the sleep clinic the evening before your test, and check in to a hotel-like room.
A technologist places painless sensors on your face, head, chest and legs to monitor brain waves, heartbeat, breathing and leg movements while you sleep. A finger clip monitors the level of oxygen in your blood. The sensors are attached by long wires to a computer, allowing you plenty of room to move around in bed.
You are allowed to watch TV or read until your bedtime, at which point you try to fall asleep. The technologist monitors your signals on a computer and by video camera from another room. He will disconnect your wires if you need to get up to use the restroom.
If your doctor suspects sleep apnea, you may be fitted with a continuous positive airway pressure (CPAP) mask at some point during the night. The CPAP mask fits over your nose, and is connected to a machine that blows air to keep your airway open.
Daytime Sleep Test at a Sleep Clinic
If you experience excessive sleepiness, you will likely undergo a multiple sleep latency test (MSLT) at a sleep study clinic. The MSLT is usually administered the day after a nocturnal polysomnogram, and consists of five nap trials throughout the day.
You receive a light breakfast about an hour before the first nap period, which begins 1.5 to 3 hours after you wake up from your polysomnogram. During the nap trial, you lie in bed and try to fall asleep while sensors monitor your sleep and wake patterns. You have a two hour break between each nap trial, during which you need to stay out of bed and keep yourself awake. You will receive a light lunch after the second trial.
Doctors use a maintenance of wakefulness test (MWT) at a sleep study center to determine how well you can stay awake. The MWT consists of four 40-minute trials, during which you try to stay awake while sitting in bed.
American Academy of Sleep Medicine. (2007). Overnight sleep study. Retrieved December 20, 2010, from http://www.sleepeducation.com/Topic.aspx?id=12
National Heart Lung and Blood Institute. (2010). Sleep studies: What to expect during a sleep study. Retrieved December 20, 2010, from http://www.nhlbi.nih.gov/health/dci/Diseases/slpst/slpst_during.html