The Sleep Lab Experience

Doctors may request a sleep study for a number of reasons but ultimately it is to try and determine if there is a problem occurring during a person's sleeping hours. This page has been created to help patients and their families understand what a sleep study is, why it has been requested and what might happen during their night in the sleep lab.

We spend about a third of our life sleeping. For this reason we can deduce that sleep is a fairly important phenomenon that helps repair and restore our bodies. Often abnormalities in sleep can disturb our daytime lifestyle. Following an examination and a thorough history by your doctor, you may be referred to a sleep disorders specialist. Your doctor might refer you to a sleep specialist for some of the following reasons:

  • You are very sleepy during the day, even after a long nights sleep
  • Your partner reports loud snoring or breathing pauses when sleeping
  • Your partner reports you thrashing about during the night (restlessness)
  • You experience choking sensations when sleeping
  • You wake with a morning headache
  • You feel depressed and/or your memory is poor

Before a diagnosis can be made on why you might experience some of these things a sleep study or polysomnography (PSG) should be performed.

The sleep study allows extensive monitoring of your bodies' activities while you sleep and allows a sleep specialist to determine whether any abnormalities are present in your sleeping pattern, muscle activity or breathing during the night. In some instances a sleep lab may have the ability to test people in their own homes or in other areas of the hospital with portable monitoring equipment.

Some of the activities of the body monitored during a sleep study usually include the following:

  • Brain activity (electroencephalogram, EEG)
  • Muscle activity (electromyogram, EMG)
  • Heart activity (electrocardiogram, ECG)
  • Eye activity (electrooculogram, EOG)
  • Chest and stomach movements
  • Airflow at nose and/or mouth
  • Body oxygen level (light transmission through finger/ear-lobe)
  • Sleeping position

If the sleep technician easily confirms that you have sleep apnea in the early part of the night you may have what is called a ‘split-night study' (half diagnosis, half titration). After about four hours of observing how you sleep the technician will wake you to initiate CPAP. While on CPAP the technician will continue to monitor you and measure the effectiveness of this treatment. This process can be done over two full nights in some cases.

A Sleep Technician (sleep tech) is the person who works at the sleep lab and conducts the sleep study. Their job is to attach the monitoring equipment to you and then observe the recordings on a computer through the night. They are also there to ensure your safety throughout your stay and to answer any further questions you might have about the procedure.

Following your night in the lab, a qualified sleep specialist will analyze your sleep study. This involves isolating any irregularities in your sleep patterns or your breathing. Often they will be trying to determine if you stopped breathing while you were sleeping and if you did they will count how often this occurred. If you had a split night study they will compare your diagnostic portion to the treatment portion to determine how effective the CPAP was for you. A summary report will be prepared outlining these things and this will determine the severity of your condition. Your sleep specialist will then contact you to outline their findings, discuss with you how you felt about the CPAP and the most suitable treatment options for you.