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Sleep Tests and Studies

When a person has obstructive sleep apnea (OSA) their airway collapses multiple times during each hour of sleep, causing the patient to briefly stop breathing. As a result of these lapses in breathing, they are likely to experience snoring, daytime sleepiness, morning headaches, and trouble focusing. Obstructive sleep apnea also comes with an increased risk of other health problems, like stroke and heart attack. Experts estimate that in the U.S., up to 93% of women and 82% of men who have OSA remain undiagnosed.

About Obstructive Sleep Apnea (OSA)

OSA occurs when breathing is interrupted during sleep. Risk factors for sleep apnea include:

Left untreated, sleep apnea can lead to serious health problems including high blood pressure, stroke, heart failure, irregular heartbeats and heart attacks.

Your first step is an exam and sleep study

If you haven’t done so already, you will meet with your primary care doctor for an initial exam and discussion of your symptoms. If your doctor determines that you may be at risk for a sleep disorder, you will then undergo a consultation and sleep study (polysomnography) at REM Sleep Diagnostics’ comfortable, quiet sleep center. You’ll enjoy a private room and comfortable bed, REM Sleep Diagnostics follows strict and proven guidelines established by the American Academy of Sleep Medicine, which assures every patient of having the most thorough, safe and accurate sleep evaluation possible.

Working seamlessly to deliver sleep solutions

REM Sleep Diagnostics will evaluate the results of your sleep study and provide your doctor with a thorough and timely report. They will then design a customized treatment plan to effectively address your sleep issues. If a CPAP or other device is indicated, REM Sleep Diagnostics will also work with you to obtain and customize this equipment to meet your individual needs. We work closely with you, your doctor, and all other parties who are involved in your health care at every step. As a result, you’ll enjoy dramatic relief from snoring and other sleep disorder symptoms. This improved sleep will make a positive difference in your work, relationships and overall health.

Two types of studies can potentially detect obstructive sleep apnea. The first is an overnight sleep study in a lab or hospital, called polysomnography. The second is a home sleep apnea test. Although a home sleep apnea test does not measure brain waves during sleep, it does measure other factors that can help medical professionals determine if a person has OSA.

Sleep Apnea Symptoms

What Is an At-Home Sleep Test?

A home sleep apnea test (HSAT) is an overnight test conducted outside of a hospital or sleep lab. HSAT can also be referred to as a home sleep test (HST), an out-of-center sleep test (OCST), out-of-center (OOC) recording, or polygraph (PG). This type of testing can accurately diagnose obstructive sleep apnea in some, but not all, people. Often, home sleep apnea testing costs less and is viewed as more convenient than an in-lab sleep study, because it takes place in the comfort of a person’s home. When undergoing a home sleep apnea test, you generally have to pick up special equipment from your doctor’s office or a sleep clinic. Then, you carefully follow the instructions provided regarding how to use the testing device given to you. You sleep as you usually would, except with specific devices connected to your body to collect data, for at least one night. Many HSAT programs have you complete the home study for two consecutive nights, this provides better chance of a successful study and improved data. After the test is completed, the equipment must usually be returned, although some newer tests are disposable. A sleep specialist will analyze the data to see if you meet the criteria for obstructive sleep apnea.

Home Sleep Studies vs. In-Lab Sleep Studies

Home sleep tests are only used to diagnose sleep-disordered breathing issues, like sleep apnea. By contrast, in-lab sleep studies can help diagnose other sleep disorders, like narcolepsy and periodic limb movement disorders. The difference lies in what the tests measure. Although both tests usually measure factors like airflow, blood oxygen levels, and heart rate, only in-lab sleep studies actually measure sleep by monitoring brain activity.

People often prefer a home sleep study to an in-lab study, since it is less expensive and does not require traveling to the sleep lab. A home sleep apnea test also involves fewer attached devices, so it may feel less invasive. However, since an in-lab sleep study gathers more data, it is more likely to pick up on symptoms of obstructive sleep apnea or other conditions.

If you have a straightforward case of moderate or severe sleep apnea and no other health conditions, then a home sleep apnea test might be right for you. If you have any reason to believe you need a more comprehensive test, then it might be worthwhile to skip the home test and go directly to the sleep lab.

Who Should Not Take a Home Sleep Study?

Although a home sleep test is useful for many people who may have obstructive sleep apnea, certain factors make it less accurate for others. Experts recommend an in-lab sleep study rather than a home study for people who are suspected to have:

Congestive heart failure
Severe or chronic pulmonary disease
Neurological or neuromuscular disorders
Other sleep disorders, like narcolepsy, parasomnias, or periodic limb movement disorder

A home sleep study may also be less accurate at detecting mild sleep apnea. If your sleep specialist suspects you have mild sleep apnea, they may recommend an in-lab study instead.

Sleep Study

If your doctor suggests you undergo a sleep study, or polysomnography, you may be wondering what is involved in this test and what to expect. Sleep studies help doctors diagnose sleep disorders such as sleep apnea, periodic limb movement disorder, narcolepsy, restless legs syndrome, insomnia, and nighttime behaviors like sleepwalking and REM sleep behavior disorder. Often these disorders cannot be identified with a normal office visit—your doctor needs to gather more conclusive evidence while you’re asleep.

What Is a Sleep Study?

A sleep study is a non-invasive, overnight exam that allows doctors to monitor you while you sleep to see what’s happening in your brain and body. For this test, you will go to a sleep lab that is set up for overnight stays—usually in a hospital or sleep center. While you sleep, an EEG monitors your sleep stages and the cycles of REM and nonREM or NREM sleep you go through during the night, to identify possible disruptions in the pattern of your sleep. A sleep study will also measure things such as eye movements, oxygen levels in your blood (through a sensor—there are no needles involved), heart and breathing rates, snoring, and body movements.

The data from your sleep study will usually be taken by a technologist, and later evaluated by your doctor. This may take up to two weeks, when you’ll schedule a follow up to discuss the results.

Types of Sleep Studies

Sleep studies collect data about what is happening in a person’s body during sleep. Different types of sleep studies are available depending on one’s symptoms and the sleep disorders that may be present.

Polysomnography

In polysomnography, a sleep technician monitors a patient who stays overnight at a specialized clinic. A variety of functions are measured throughout the night, including eye movements, brain and muscle activity, respiratory effort and airflow, blood oxygen levels, body positioning and movements, snoring, and heart rate.

Multiple Sleep Latency Test

Multiple sleep latency testing measures how quickly someone falls asleep and how quickly they enter REM sleep during daytime naps. This test is primarily used to diagnose excessive daytime sleepiness that may be due to narcolepsy or an unknown cause (idiopathic hypersomnia).

CPAP Titration

Continuous positive airway pressure (CPAP) is a common treatment for sleep apnea. In CPAP titration, a technologist determines the amount of air pressure that patient needs from their CPAP so that their machine can be properly programmed for home use. CPAP titration usually requires a second sleep study. When sleep apnea is strongly suspected, a split-night sleep study2 may be an option. In a split-night study, polysomnography is used to diagnose sleep apnea during the first half of the night, and CPAP titration is performed during the second half of the night.

Home Sleep Apnea Testing

Home sleep apnea testing collects data about a patient’s breathing, heart rate, and other variables overnight. However, compared with polysomnography, home testing provides less information, and the process is not overseen by a technologist.

What Can a Sleep Study Diagnose?

A sleep study is used to diagnose many sleep disorders, including:

Insomnia
Sleep Apnea
Restless Leg Syndrome
Narcolepsy

Periodic Limb Movement Disorder
Sleepwalking
Sleep Talking (Somniloquy)
REM Sleep Behavior Disorder

Who Needs a Sleep Study?

When you visit a clinic for polysomnography, you will be assigned a room to yourself. Before bedtime, a technologist glues or tapes painless sensors to your head and body that will record information. If you need to use the bathroom, the technologist will detach the sensors and reattach them when you return.

You can read and relax in bed until it is time to go to sleep. The technologist will be on hand to monitor and record the results of your test and to assist you with any issues during the night. The sleep test ends when you wake up in the morning and have the sensors removed.