What to Expect During Your Sleep Study Test
Types of Sleep Studies
There are many reasons why you may be having a sleep study. I will explain what to expect and everything you need to know to prepare mentally and physically for your upcoming study. I am a registered sleep technologist and have performed hundreds of sleep studies.
In doing so, I have learned that most patients feel uninformed prior to this experience, and they do not have full comprehension of the process. There's no need to worry—this is a painless test and is well worth your time. You don't even have to study for this test!
If the doctor orders a sleep test it is generally polysomnography and you would be treated as a clinical patient.
The Sleep Test
Each lab is different but the main prerogative is the same. A clinical sleep study is done to see what exactly is going on when you are sleeping. The video below is a great example of how a sleep test should be conducted. Many labs look just like the video clip and the procedure is done the same way.
Here's What You May Not Know
- You will be fitted with about 23 electrodes for a normal sleep study. The electrodes are wires that are attached to a box with which the signals are transmitted to a computer while they are on you. The electrodes must be filled with a paste that is conducive to electricity. Patients hate the paste and while it is difficult to wash out of the hair it is only used sparingly where the actual electrodes are placed. The tech will use a gritty gel to gently abrade the top layer of skin. This is necessary to get a good, clear signal for the test. Dead skin cells make the signal look junky on the screen.
- If the electrode is to be placed on the skin it will usually be taped on with an adhesive tape that is made for this purpose. Notify the lab if you have an allergy to adhesives or latex.
- There will be electrodes placed approximately 1 centimeter up and 1 centimeter away on one side, one centimeter out and 1 centimeter down from one eye. This is to detect your eye movements and how much time you spend in REM. Usually before a person falls to sleep they will have slow, rolling eye movements. Your technologist will be watching for this and noting the time it took you to fall asleep.
- The normal person takes about 10 to 20 minutes to fall asleep this is known as your sleep latency. When you go into REM your eyes will suddenly jerk around and begin moving rapidly. This stage of sleep usually takes about 90 minutes for the normal sleeper to achieve and will be noted as your REM latency.
- You will have a few electrodes placed just on the chin, near or under it depending on the lab. These are used to see the muscle tension in your chin or will detect a case of bruxism (teeth grinding).
- Electrodes and a band may be placed on or around your ribcage area. These are to detect the pattern of your respirations. When you sleep your body should work to breathe all by itself....if the muscles stop working to breathe it can be an indicator for different types of medical conditions.
- You will have electrodes on your clavicle area. These are electrodes that are a partial EKG (electrocardiogram). While it is not a complete EKG there are enough leads to see if there is something unusual going on with the heart function or if apneic events, for instance, trigger a reaction in the heart. Your heart rate and rhythm will be monitored and noted for the duration of the study.
- You will have electrodes on your legs and possibly your arms. These leads are used to detect your arm and leg movements when you sleep. Sometimes people have a condition called Periodic Limb Movement Disorder or apneic event can cause a person to jerk themselves awake. Each body movement will be noted.
- You will have a plastic tube that is placed below the nostrils called a nasal cannula. This piece is very important as it tells us when you are breathing and if you are breathing through the mouth or the nose.
- A small microphone will be taped on the neck area that will record the vibrations of the snoring.
- Most sleep studies are recorded in video and sound. A camera with infrared lights will be in the room and audio is recorded by a very small microphone that is activated by sound. The camera is needed to see which position you are sleeping in and each time you change positions a note will be made. Apnea tends to be worse when a patient is sleeping on their back.
- Sound is recorded so that the frequency and intensity of snores can be noted. (Usually mild, moderate or loud).
- Each piece of equipment is needed. The body gives off clues for specific conditions but it is much like a puzzle. We need to look at all of the pieces together to see the entire picture of your sleep.
- It is more difficult to fall asleep with the equipment on but most of the patients do much quicker than they think. The brain has a way of taking over and you drift off to sleep because it is your body's natural need. If you do experience anxiety speak to your doctor prior to the study. They do not like to prescribe sleep drugs because it is most beneficial to see you as you normally sleep. Many drugs affect your brain and sleep. Some drugs suppress REM, some drugs suppress respiratory effort.
- Just prior to lights out...the technologist will calibrate the equipment and make sure that everything is working right prior to the start of the study. The tech will give you a series of commands such as blink your eyes 3 times, grit your teeth, hold your breath...and so on. This is done to make sure that every single movement you make is picked up on the screen and being recorded.
Next it is lights out. If you need to use the restroom just speak up—the sound is on!
Sleep research is still in its infancy. There is much to be learned and the more science shows that sleep affects wake, the more we realize we need to know. For this reason, there are different sleep research studies that you may be able to participate in and get paid for your time. The center I worked for did sleep studies in conjunction with many universities and pharmacological companies, such as Pfizer and Merck. Drugs for sleep commonly must be approved by the FDA so sleep centers may be employed to conduct investigational studies to test a particular drug. Contact your local sleep centers or colleges and ask if they are conducting any studies if you are interested in being a participant. You can also google the words: Investigational, research, studies and your state and you may find links to the labs near you that conduct these type of studies.
Research studies may or may not include the use of an investigational drug. The purpose of the study may not be to test a drug. I have been involved in studies where the government was testing to see why people have more accidents working on the night shift. We would have these subjects sleep all day and make them stay awake all night performing "work tasks." They might be asked to do a series of simple to more complicated tasks. The purpose might be to test for reaction time or to see how fast you fall asleep.
If you want to participate in an investigational study there are also certain laboratories that do nothing but conduct research studies in all kinds of fields and pay the subjects. You should read all of the fine print, find out if you will be taking a drug and I would recommend that you find out everything you can about that drug before swallowing it. Don't be a guinea pig for money—and make sure it is an accredited facility.
I love sleep. My life has a tendency to fall apart when I am awake, you know?— Earnest Hemingway