A sleep study consists of a number of medical tests performed at the same time during sleep. The tests measure specific sleep characteristics and help to diagnose sleep disorders. A sleep study may also be referred to as a polysomnogram.
Reasons for Getting Your Sleep Evaluated
- If you regularly have difficulty getting to sleep or staying asleep
- If you have a problem with snoring. Has anyone ever told you that you have pauses in breathing or that you gasp for breath when you sleep?
- If your legs “active” at night. Do you experience tingling, creeping, itching, pulling, aching or other strange feelings in your legs while sitting or lying down that cause a strong urge to move, walk or kick your legs for relief?
- If you so tired when you wake up in the morning that you cannot function normally during the day
- If sleepiness and fatigue persist for more than two to three weeks
Risks of Sleep Studies
Sleep studies are painless. Your skin may be red or itchy from the glue used with the electrodes. There are no other risks with sleep studies. The irritation will go away once the sensors are removed.
Before the procedure
The sleep clinic doctor will explain the procedure to you and offer the opportunity to ask questions that you might have.
- You may be asked to restrict your sleep before the study, avoiding naps for example.
- Notify the sleep clinic doctor of all medications (prescription and over-the-counter) and herbal supplements that you are taking, as they may alter test results.
- Avoid caffeine-containing products for several days before the testing as they may cause you to take longer to fall asleep.
- Sedatives should not be used during the sleep study as they can alter results. But if you typically use a prescribed or over-the-counter sleep medication, or if you have insomnia, check with the sleep clinic doctor about taking your medication so that you will sleep adequately during the study.
- A sleep questionnaire or diary may be given to you (and your bed partner, if applicable) to complete ahead of time. Do your best to provide the most accurate responses.
- Showering before going to the sleep lab may be helpful; however, avoid using lotion or oil on your skin because the electrodes may not adhere to the skin.
- You may be encouraged to bring your own pyjamas and pillow.
- If needed, you may be able to shower and dress for work the morning after the sleep study.
- Based on your medical condition, the sleep clinic doctor may request other specific preparation.
During the procedure
A sleep study is generally performed on an outpatient basis at night. Procedures may vary depending on your condition and the sleep clinic doctor's practices.
Generally, a sleep study (polysomnography) follows this process:You will be asked to remove any jewellery or other objects that may interfere with the procedure.
- You will be asked to change into pyjamas or a hospital gown.
- Small metal discs, or electrodes, will be positioned on your head and body for EEG, ECG, EOG, and EMG cables.
- Pulse oximetry, which measures the oxygen level in the blood vessels, and air flow monitors, which measure breathing, will be applied to the finger and face, respectively.
- The temperature of the room may need to be maintained at a certain level, but blankets can be adjusted as needed.
- Lights will be turned off and monitoring will begin before you fall asleep.
- For multiple sleep latency testing (MSLT), short nap periods will be assigned at intervals.
- For multiple wake testing (MWT), you will be asked to try and stay awake for certain periods of time.
- When the study has been completed, the electrodes and other devices will be removed.
Generally, no special care is required after a sleep study and results may take several days. However, the sleep clinic doctor may give you additional or alternate instructions after the procedure, depending on your particular situation.
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