Overnight Sleep Study (Polysomnogram)

A sleep study (polysomnogram) is ordered by your sleep doctor.

The sleep study takes place in a private room with a bed in the sleep lab. You will stay overnight. The test records important details about your sleep, including the following: 

• Brain waves
• Eye movements
• Muscle tension
• Heartbeat
• Breathing patterns and effort
• Leg movements
• Blood oxygen level

• Please do not nap (except if you have narcolepsy) or take recreational drugs for at least one week prior to, and during, your sleep study.
• Do not consume caffeine (coffee, tea, cocoa and chocolate) after noon (12 p.m.) on the day of your test.
• If your doctor wishes your study to be completed on your current medications, they will tell you this.
• Shower and shave beforehand as well as remove hair pieces. Remove nail polish or false nails from at least one index finger for oxygen monitoring. 

Check in typically occurs at 7:45 p.m. Please report directly to the sleep lab located on the ground floor of the Purdy Pavilion. On weekends and holidays, report directly to the main lobby of the Koerner Pavilion. Click here to find out how to get here.

After you check in, a team member will take you to your room and explain the steps for your sleep study. You will be asked some questions about your current health and your sleep. Please ask our team any questions or share any concerns.

The study takes place overnight and finishes between 7:30 and 8:00 a.m. Wake-up is typically between 5:30 and 6:00 a.m. You can buy breakfast in the hospital cafeteria during weekdays. If you are staying for a daytime test (called a Multiple Sleep Latency Test) you may bring breakfast or lunch, or buy food in the hospital cafeteria during weekdays.

If you need a second night of testing, the technologist will tell you when you should come in.

Quick facts: 

• The test is “non-invasive”, which means no needles (exception: if your doctor ordered blood tests, you may need a separate blood test in the morning).
• We use gel to attach electrodes. The gel easily washes out of your hair after the study.
• It takes about one hour to get you ready for the study.
• The technologist will be available in the next room and will monitor you at all times.
• You can be disconnected during the study if you need to use the restroom or walk around.

Your doctor may ask you to stay at the sleep lab after you complete the overnight sleep study. The purpose is to do an additional daytime test called the Multiple Sleep Latency Test (MSLT). This is to test your propensity to fall asleep, and for the presence of narcolepsy. 

This test consists of four to five scheduled twenty-minute naps throughout the day, and runs from 8:30 a.m. to approximately 5:30 p.m., depending on the results during the day.