What is a Sleep Study (Polysomnograph)? 

Overnight Polysomnograph (Detailed Sleep Study) Performed In The Sleep Center

An overnight visit to a sleep center is likely to be a new experience for you. A sleep study or polysomnogram (Somnus=sleep) is a recording that includes measurements used to identify different sleep stages and classify various sleep problems. 

Sleep is not a simple process. Many parts of the brain control it and influence its different stages. These levels or stages of sleep include drowsiness, light sleep, deep sleep, and dream sleep, It is possible identify which stage of sleep a person is in by measuring different activities of the brain and body. However, it is not possible to identify if you are dreaming or what you are thinking about subconsciously!

During sleep testing, the activities that go on in your body during sleep including brain waves, muscle movements, eye movements, breathing through your mouth and nose, snoring, heart rate, and leg movements are monitored by small metal discs (called electrodes) applied to your head and skin with an adhesive. Flexible elastic belts around your chest and abdomen measure your breathing. A clip on your index finger or earlobe monitors the level of oxygen in your blood and your heart rate. Your sleep may also be videotaped for later review of any abnormalities observed during the study. The sleep technician will let you know if this is done.

None of these devices are painful and all are designed to be as comfortable as possible. If you have questions or concerns about the application of the electrodes, speak with the technician when you arrive at the center.

Why do I need a sleep study?

In order to fully understand your sleep and any problems with it, we need to look at various brain activities and body systems and their relationships throughout the night. After the study, a sleep specialist will review and interpret the record to help you understand your specific sleep patterns. Treatment recommendations will be made if evidence of a sleep disorder is found.

The sleep study and its analysis and interpretation are part of a complex process. Many hours of work are required by specially trained professionals, who process or “score” the large amount of data recorded during the study. A sleep specialist with special knowledge of sleep and its disorders then interprets the information. A typical sleep study involves more than 800 pages of data of various kinds (for example, brain waves, muscle movements and eye movements), which are digitally recorded. Because this is a time-consuming and labor-intensive process, sleep studies are usually not evaluated immediately, and it may take some time to receive the results of your study.

How will I be able to sleep in a strange environment with all those wires on me?

This is the question asked most frequently by patients prior to their sleep studies. Most people do without any significant problem! Many people expect the sleep center to be cold, bright, technical and impersonal-looking. However, every effort has been made to ensure that the surroundings (and especially the bedroom) are homey and comfortable, like a hotel room.

The technical equipment and technicians will be in a room separate from your sleeping room, and the electrode wires will be gathered together in a kind of ponytail behind your head so that you will be able to roll over and change positions almost as easily as you would at home.

The electrodes may feel strange on your skin at first, but most people do not find them uncomfortable or an obstacle to falling asleep. The sleep specialist recognizes your sleep in the center may not be exactly like your sleep at home. This usually does not interfere with obtaining the necessary information from your study.

What are the specific instructions I should follow on the day of the sleep study?

  • We encourage ONE of your family members or friends to accompany you for the study.
  • Remember to wear loose fitting, comfortable clothing that button up in front.
  • Avoid caffeine (coffee, tea, cola, chocolate) if possible after 2:00p.m.
  • Avoid alcohol if possible.
  • Try not to nap.
  • Before coming to the sleep center, wash and dry your hair, and do not apply hair sprays, oils or gels
  • Pack an overnight bag, as you would for an overnight stay at a hotel or a friend’s house. This may include comfortable overnight clothing, toiletries etc.
  • If you prefer, you could bring your own pillow.
  • Please take all your usual medications unless specifically advised otherwise. DO NOT discontinue any prescription medication without first talking to the sleep specialist.

What will happen when I arrive at the sleep center?

You should schedule a follow-up visit with the doctor to discuss the results and recommendations for treatment. Be sure to inquire before your study about scheduling a follow-up visit. Sleep study results are not generally discussed over the telephone because of their complex nature. To fully understand the results of your sleep study, their implications, and any treatment recommendations that are made, you should meet face-to-face with your healthcare professional.

Additional procedures are occasionally needed to establish a diagnosis or plan a treatment. Your sleep specialist will discuss this with you.

Portable Sleep Study

The overnight polysomnograph, which provides several details about your sleep is the ideal way to analyze sleep. However, due to logistic reasons, your sleep specialist may discuss with you the other option, which is a portable sleep study which could be done at a location outside the sleep center. This could be your home or a friend or relative’s place or a hotel room, details of which you could discuss with your doctor. Please note that this portable sleep study may be acceptable alternative in some situations, but may not provide all required information, if a detailed analysis is required. It is important for you to discuss this with your sleep specialist.

If a portable sleep study is planned, a technician comes to your place and hooks up a portable machine (almost of the size of a cell phone). You may freely move around and perform any routine activity with this equipment. The technician explains how to unhook the machine on the following day and will come back and pick it up. This is then analyzed and you will need to schedule an appointment to discuss the results.