Polysomnography is a sleep study that can help doctors diagnose sleep disorders. A person can take the study in a sleep center or at home.
In this article, we look at why a person may need to undergo polysomnography and what happens during the procedure.
Polysomnography is a test that doctors use to diagnose sleep disorders. People sometimes refer to it as a sleep study.
The test provides detailed information about a person’s sleep, including the duration and quality.
The attachment of sensors to a person’s body makes it possible to monitor and record:
- brain waves
- heart rate
- eye movements
- limb movements
- oxygen in the blood
- chin muscle activity
Doctors consider polysomnography to be an excellent method for diagnosing obstructive sleep apnea (OSA).
OSA is a disorder in which a person frequently stops breathing in their sleep.
In the United States, it affects 5% of females and 14% of males.
Experts are increasingly recognizing OSA as a risk factor for deaths due to cardiac, neurologic, and surgical causes.
Other conditions and symptoms that polysomnography can test for include:
A person should expect to stay overnight in a sleep center for their sleep study.
On the day of the study, a person can perform their usual daily activities, but they should avoid:
- stimulants, such as caffeine
- using hairsprays or gels
If a person is taking any medications, they should speak to the sleep specialist or doctor to ensure that they can continue taking them.
The individual will usually need to arrive in the early evening and bring comfortable clothes to sleep in, along with toiletries and clean clothes for the morning.
A healthcare professional will glue or tape sensors to the person’s body. The wires are long enough to let a person move around and turn over in their sleep.
At the start of the test, the healthcare professional will ask the person to move their eyes, clench their teeth, and move their legs to make sure that the sensors are working.
Many people do not sleep as well as they might at home because of the sensors and unfamiliar surroundings, but this typically does not affect the results.
Sleep studies usually end in the early hours of the morning.
Following the removal of the sensors, a person can return home.
A home test may be a convenient way to collect information about a person’s sleep.
The American Academy of Sleep Medicine (AASM) guidelines advise that a doctor can use a home test if a person is at higher risk for moderate-to-severe OSA.
However, a home test is not an option if a person has any of the following health conditions:
- significant heart and lung disease
- neuromuscular conditions
- history of stroke
- history of chronic opioid use
- significant sleep disorders
Before the test, a person will need either to collect the equipment from their doctor’s office or to request its delivery to their home.
A member of the sleep team will give a person instructions on how to use the equipment and provide an opportunity to ask any questions.
At their regular bedtime, the person will attach sensors to their body in the way that the doctor instructed.
When the person wakes up in the morning, they will remove the sensors. They may have to return the equipment by mail or take it back to the center.
The AASM recommend that unattended assessment should only take place in conjunction with a comprehensive sleep evaluation.
According to a 2019 study in the journal Sleep Science, polysomnography tests have limited access, long waitlists, and high costs.
The study indicated that polygraphy, which is a portable sleep monitor, may be a useful alternative way to test for OSA.
There are smartphone applications that can monitor sleep, but according to 2015 research, their results do not correlate with those of polysomnography.
It may take up to 2 weeks for members of the sleep team to interpret the information.
A board-certified sleep specialist will contact the person to discuss the results and diagnosis.
If the person underwent the test at home, and it is necessary to repeat the test, this will typically take place in a sleep test center.
Depending on the results, a person’s doctor will discuss any further options or treatment with them.
Polysomnography does not usually carry any risks.
However, in some cases, a person might react to the adhesive that attaches the sensors to their body. If they are concerned about this, they should speak to the technologist beforehand.
The cost of polysomnography may vary.
According to Medicare.gov, a person can pay 20% of the Medicare-approved amount after they have paid a deductible.
The final cost will also depend on:
- any other insurance that a person has
- the type of facility in which the sleep study takes place
- how much the person’s doctor charges
Polysomnography is a useful tool to find out about sleep disorders that may be affecting a person’s life or health.
It can test for OSA, which can have associated health risks.
Home tests are available, but they may not be suitable for everyone. The data that they collect may not be as accurate as the data that a sleep center provides.
Practicing good sleep hygiene can sometimes help a person have better sleep. They may benefit from:
- having a regular bedtime and wake time
- avoiding daytime naps
- exercising regularly, but not too late in the evening
- limiting caffeine, particularly in the latter half of the day
- using the bedroom only for sleep, and avoiding watching TV or working in there
- keeping the bedroom at a comfortable temperature and as dark as possible
- avoiding the blue light from screens and technology before bedtime
If a person thinks that they may have sleep apnea or any other sleep disorder, they should discuss this with their doctor.