SLEEPWiser

How do you know which test you need? The first step is meeting with a healthcare provider. They will discuss your symptoms, sleep habits, medical history, and daytime concerns before deciding whether testing is needed and which type of test is most appropriate.

What Can a Sleep Test Measure?

Depending on the type of test, sleep testing may record brain waves, eye movements, muscle activity, heart rate, breathing, airflow, oxygen levels, body position, snoring, and leg movements. These measurements help show when you are asleep, which stages of sleep you enter, and whether anything interrupts your sleep.

Sleep studies are generally painless. Sensors are attached to the skin and record information while you sleep.

Overnight Sleep Study

An overnight sleep study is also called polysomnography, or PSG. It is usually performed in a sleep center or hospital sleep laboratory. You will sleep in a private room while a sleep technologist monitors the recording from another room.

Small sensors are placed on your scalp, face, chest, legs, and finger. Flexible belts are placed around your chest and abdomen to measure breathing effort. The equipment may look like a lot, but you can still move, change positions, and use the restroom during the night.

What Can an Overnight Study Diagnose?

An overnight sleep study can help evaluate sleep apnea, unusual movements, nighttime behaviors, seizures, and other conditions that disrupt sleep. It also provides information about sleep stages, awakenings, breathing patterns, oxygen levels, and heart rhythm.

Home Sleep Apnea Test

A home sleep apnea test, often called an HSAT, is a simplified test that you complete in your own bed. The equipment usually measures breathing, airflow, oxygen levels, heart rate, and breathing effort.

Home testing is primarily used to evaluate possible obstructive sleep apnea in certain adults. It does not collect all of the information recorded during an overnight laboratory study and is not appropriate for every patient. A healthcare provider must determine whether home testing is suitable for you.

Multiple Sleep Latency Test

A Multiple Sleep Latency Test, or MSLT, measures how quickly you fall asleep and if certain stages of sleep are achieved, particularly REM (Rapid Eye Movement). It is commonly used when narcolepsy or another cause of excessive daytime sleepiness is suspected.

The test is usually performed the day after an overnight sleep study. You are given five scheduled naps, two hours apart, during the day while sensors record your brain waves, eye movements, and muscle activity.

Maintenance of Wakefulness Test

A Maintenance of Wakefulness Test, or MWT, measures how well you are able to stay awake during the day.Unlike the MSLT, where you are asked to try to fall asleep, the goal of the MWT is to see how long you can remain awake in a quiet, dimly lit room.

The test is usually performed during the day following an overnight sleep study or after treatment has begun. You are given four scheduled tests, two hours apart, where you sit comfortably in a darkened room and try to stay awake while sensors record your brain waves, eye movements, and muscle activity.

An MWT may be used to evaluate how well treatment is controlling excessive daytime sleepiness or to determine whether a person can safely perform activities that require sustained alertness.

Actigraphy

Actigraphy is a test that measures your sleep and wake patterns over several days or weeks. Instead of spending the night in a sleep center, you wear a small device, similar to a wristwatch, that records your movement throughout the day and night.

The information collected helps your healthcare provider understand your sleep schedule and identify irregular sleep patterns. It is commonly used to evaluate insomnia, circadian rhythm sleep disorders, and other conditions that affect when you fall asleep and wake up.

During the testing period, you may also be asked to keep a sleep diary. Comparing the information from your diary with the actigraphy data provides a more complete picture of your sleep habits.

Preparing for Your Sleep Test

• Follow the instructions provided by your sleep center or healthcare provider.
• Wash and dry your hair before an overnight study.
• Avoid hair products, lotions, oils, and heavy makeup unless instructed otherwise.
• Bring comfortable sleepwear and any medications you normally take.
• Ask whether you should avoid caffeine, alcohol, naps, or certain medications before the test.
• Bring your usual CPAP mask or equipment if the sleep center asks you to.
• Continue your normal routine unless you receive different instructions.

After Your Sleep Test

A sleep technologist collects and reviews the recorded information, but the technologist does not provide the final diagnosis. A qualified healthcare provider interprets the complete study and discusses the results with you.

Your results may show that no treatment is needed, that more testing is recommended, or that treatment should begin. Treatment depends on the condition identified and may include lifestyle changes, positive airway pressure therapy (CPAP), medication, behavioral treatment, or another approach.

Frequently Asked Questions

Will I be able to fall asleep with all the sensors?

Most people worry they won’t sleep during a study, but even a few hours of sleep usually provides enough information for the sleep specialist to evaluate breathing, movement, heart rhythm, and sleep stages.

Is a sleep study painful?

No. The sensors are attached with adhesive or soft wraps and simply monitor your body’s activity while you sleep. The test is completely noninvasive.

Can I use the restroom during the study?

Yes. If you need to get up during the night, simply let the technologist know. The sensors are designed so they can disconnect and reconnect you safely.

What if I normally sleep on my stomach?

Most people are encouraged to sleep in their usual position whenever possible. If you naturally change positions during the night, the sensors are designed to move with you.

How long does it take to get my results?

The recorded data must be reviewed and scored by a registered sleep technologist before being interpreted by a sleep physician. Results are often available within one to two weeks, depending on the sleep center.

Will I be diagnosed the same night?

Usually not. The information collected during the study requires careful review before a diagnosis is made. Your healthcare provider will discuss the results and recommend treatment if needed.

What happens if sleep apnea is found?

If significant sleep apnea is identified, your provider may recommend treatment such as CPAP therapy, oral appliance therapy, weight management, positional therapy, surgery in selected cases, or additional testing depending on your individual needs.

Can I drive home after the test?

Yes. Most overnight sleep studies end early in the morning, and patients can usually drive themselves home unless their healthcare provider has given other instructions.

References

American Academy of Sleep Medicine. (2023). Clinical Use of a Home Sleep Apnea Test: An Updated American Academy of Sleep Medicine Position Statement.
https://aasm.org/advocacy/position-statements/clinical-use-of-a-home-sleep-apnea-test-an-updated-american-academy-of-sleep-medicine-position-statement/

American Academy of Sleep Medicine. (n.d.). Sleep Education.
https://sleepeducation.org/

National Heart, Lung, and Blood Institute. (n.d.). Sleep Studies.
https://www.nhlbi.nih.gov/health/sleep-studies

National Heart, Lung, and Blood Institute. (n.d.). Sleep Apnea.
https://www.nhlbi.nih.gov/health/sleep-apnea

National Institute of Neurological Disorders and Stroke. (n.d.). Narcolepsy Fact Sheet.
https://www.ninds.nih.gov/health-information/disorders/narcolepsy

Mayo Clinic. (n.d.). Polysomnography (Sleep Study).
https://www.mayoclinic.org/tests-procedures/polysomnography/about/pac-20394877

Mayo Clinic. (n.d.). Sleep Apnea.
https://www.mayoclinic.org/diseases-conditions/sleep-apnea/symptoms-causes/syc-20377631

Cleveland Clinic. (n.d.). Sleep Study (Polysomnography).
https://my.clevelandclinic.org/health/diagnostics/12131-sleep-study-polysomnography

MedlinePlus. (n.d.). Sleep Studies.
https://medlineplus.gov/lab-tests/sleep-studies/