What to Expect from a Sleep Study

Dr. Dan JensenSleep Study

What to Expect from a Sleep Study
Dr. Dan Jensen

Sometimes a diagnosis for a sleeping disorder is best made from observing a person while they are sleeping. If this is the case for your medical care, your doctor may recommend you do a sleep study – also called polysomnography- to better understand if sleeping issues are present and what the best course of treatment should be.

If you have never done a sleep study before, don’t worry- it is an overnight test that is simple and non-invasive. Sleep studies are the most definitive way to observe and diagnose conditions like sleep apnea, restless leg syndrome, insomnia, narcolepsy and REM sleep behavior disorder. Let’s go over what happens in a sleep study so you know what to expect from the testing.

Preparing for Your Sleep Study

Your sleep study will involve an overnight stay at a sleep study or hospital. You’ll be expected to arrive approximately two hours before your scheduled bedtime. The room you will sleep in will be private, dark and comfortable for an optimal sleeping experience. For your overnight stay you are allowed to bring sleep-related personal items, including your own sleep wear.  

The sleep study is going to monitor your REM sleep cycles, track your eye movement and monitor the oxygen levels of your blood. Brain wave patterns that indicate REM sleep will be obtained by placing flexible electrodes on your face and scalp that connect to an EEG machine. The EEG electrodes sense the small electrical pulses generated by brain and muscle actions, recording them for study.

Blood oxygen will be monitored with a small external finger sensor. Your sleep technologists will prep you for sleep by attaching data sensors and making sure you can move comfortably while they are attached. You may also be asked to wear a belt-like sensor that can measure your breathing while you sleep.

Other Equipment

Depending on what you are being tested for, other various sensors may be present while you sleep. Testing for sleep apnea often involves a snore microphone and a nasal airflow sensor. You may also have electrodes placed on your chest to record an electrocardiogram to chart your heart’s activity during the night. Breathing, heart and snoring monitors are especially needed to test for the presence of sleep apnea patterns.


At your bedtime, your room will be darkened and you will be encouraged to relax and fall asleep while monitoring begins.  The sleep lab is a quiet space designed for sleeping comfort as well as observation. Any cords and connections to monitoring equipment will be soft and flexible, as well as long enough to allow you to change positions while you sleep. Your sleep technologists will show you how to contact them if you need assistance during the night, such as a trip to the bathroom.

Sleep technologists will be gathering data from you during your overnight stay.  By analyzing the data, they can see if there are irregularities or disruptions with your sleep cycle. Your study will encompass a full night’s sleep, but if only partial data is obtained it can still be relevant to a sleep diagnosis. If you sleep through the night, your sleep technologist will gently wake you up in the morning when the study is complete. Although people often worry they will not be able to sleep while attached to monitoring equipment, the vast majority of sleep study patients find that adjusting to the study equipment is not a problem.

Getting Results

Your overnight sleep study will generate a body of data that can then be analyzed for sleep issues. Your sleep technologists are in charge of gathering and organizing your sleep data for your doctor. Your doctor will then review the data. The entire process can take up to two weeks, so results won’t be immediately available after your overnight stay.

Once the data has been looked at, your doctor will contact you to follow up with results. The next step may be treatment and care for an observed condition. Sometimes more sleep study will be recommended to fully understand the issue.

Sound Sleep Medical

If you have been having trouble getting a full night’s rest, it is time to set up an appointment with Sound Sleep Medical. Here, helping you get the restful sleep your body needs is our specialty. We have over 25 years of experience in the Salt Lake City area helping people connect with sleep resources and solutions for happier, healthier living.