Sleep Troubles? You May Need a Sleep Study

The overnight evaluation can help pinpoint potentially dangerous problems. Here’s how it works and what to expect

Michael Schroeder,

AARP

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En español

Published March 17, 2025

AARP (Getty Images)

Some people can’t fall asleep at night; others drift off easily but awaken in the wee hours. Some people snore, and some act out their dreams. Whatever goes bump in the night, sleep troubles aren’t without consequence.

Left unchecked, undiagnosed and untreated, sleep disorders can start the dominoes falling, dangerously disrupting cardiovascular function, undermining overall health and making it difficult to get through the day. That’s why you should never resign yourself to poor sleep, says Clete Kushida, M.D., a neurologist specializing in sleep disorders. Instead, talk to your doctor, who can help determine the root cause of your overnight issues.

“We know that sleep and sleep disorders have a profound impact on health,” says Kushida, a professor of psychiatry and behavioral sciences and medical director of sleep medicine at Stanford University.

Sleep loss and sleep deprivation — independent of sleep disorders — can be disruptive and can affect your health in some ways, for example, with weight gain. “But with sleep disorders, like obstructive sleep apnea, there’s a strong link [to] endocrine disorders, high blood pressure, stroke, heart attack — all these things,” Kushida says.

Research conducted by AARP finds that 70 percent of adults ages 40 and older experience sleep difficulties. However, 4 in 10 adults with untreated sleep issues presume that their poor sleep isn’t that serious.

What can you learn from a sleep study?

Health risks of interrupted sleep

Untreated sleep disorders can increase your risk of several health conditions, including:

Heart failure
High blood pressure
Stroke
Diabetes
Depression

Sleep tests can help your doctor diagnose sleep-related disorders.

Source: National Heart, Lung and Blood Institute

Uncovering what’s happening when you turn out the lights can take some detective work, so often doctors will refer patients with sleep issues — or suspected disorders — for a sleep study to evaluate what’s happening when you’re dozing, says Fariha Abbasi-Feinberg, M.D., a spokesperson and board member of the American Academy of Sleep Medicine and medical director of sleep medicine for Millennium Physician Group in Fort Myers, Florida.

That includes monitoring a person’s breathing, heart rate and other vital signs. According to Medicare claims data, hundreds of thousands of these studies are conducted each year among older adults.

The aim of a sleep study is to pinpoint what kind of issues a patient is struggling with overnight. There are around 90 different sleep disorders, which are grouped into six major categories, Kushida says, including:

Insomnia, defined as difficulty falling or staying asleep or waking up too early.
Circadian-related sleep disorders, like delayed sleep-wake phase disorder, which causes a person to stay up and wake up later than they want.
Sleep-related breathing disorders, such as sleep apnea, where relaxed throat muscles block the airway, stopping breathing many times a night.
Sleep-related movement disorders, like restless legs syndrome.
Parasomnias, which are unusual behaviors during sleep, like sleepwalking and REM sleep behavior disorder.
Narcolepsy and hypersomnias, characterized by excessive daytime sleepiness.

Not every sleep study results in a diagnosis; and sometimes, multiple studies might be needed. But the data gathered helps doctors piece together what’s going on by documenting everything from a patient’s breathing difficulties to changes in heart rate and brain activity as well as significant movement overnight, Kushida notes.

“Additionally we have daytime tests that can also help to diagnose if the person has significant daytime sleepiness or might have things like narcolepsy,” Kushida says.

What does a sleep study entail?

Though some people might be able to do a sleep study at home, these tests typically occur in a sleep lab, which is often a room at a sleep medicine center where a patient can be monitored overnight.

With an at-home sleep test, a small portable device monitors a person’s breathing and oxygen intake while they’re sleeping. “It is basically a respiratory monitor that is used to determine if a patient has sleep apnea or not,” explains Ana Krieger, M.D., medical director of the Center for Sleep Medicine at Weill Cornell Medicine in New York City.

While home tests are becoming more sophisticated, doctors say they’re often used to diagnose or rule out sleep apnea. “It’s really not a good test if the doctor’s concerned about something else,” Krieger says.

On the other hand, in-lab sleep studies offer a more comprehensive look at what’s happening overnight and boast more intricate technologies.

Krieger says the diagnostic tools used in the lab, collectively called polysomnography, have far more wires and cables than the at-home study devices. These added wires are attached to the patient’s head and face to monitor brain activity and the electrical activity of the heart, similar to an EKG (electrocardiogram) a patient might get while awake.

A technician watches the patient and their vitals overnight. After the sleep test, the data is shared with a doctor who has special training in the diagnosis and treatment of sleep disorders.

“Sometimes you can attach monitors to the arms and legs for patients that move a lot at night, or that you might want to evaluate because they might have Parkinson’s disease, they might be acting out dreams, or they might be having leg cramps at night,” Krieger says. “So we can always add more monitoring cables to evaluate the underlying problem.”

All these intrusions into one’s personal space make sleep studies a challenge, especially since they are supposed to reflect real life. (And who can fall asleep with cables all over their body?) But accommodating patients — keeping the room quiet, comfortable, cool and dark, for example — is all part of it.

“It’s awkward,” Abbasi-Feinberg admits. “Interestingly though, most people, once they sort of settle in, do sleep.” And imperfect zzz’s still provide invaluable data that helps clinicians more expertly evaluate sleep woes.

Sleep studies are also low-impact and low-risk. “It’s not dangerous to have a sleep study in any way,” Abbasi-Feinberg says.

Given the dire impact that untreated sleep disorders can have on a person’s life and health, Kushida urges those who aren’t sleeping well to get help. If you’re sleepy, your sleep is interrupted during the night, you (or a partner) notice any unusual behaviors during sleep, or you just can’t fall asleep, “definitely seek evaluation,” he says.

What to know before you go

To get the most from your sleep study, consider the source: Experts advise patients to go to accredited sleep medicine centers. To find a sleep clinic near you that’s accredited by the American Academy of Sleep Medicine, go to sleepeducation.org, and enter your ZIP code. These centers typically offer at-home sleep tests as well.

“Many other companies out there or online services perform tests with equipment that is not necessarily very valid,” Krieger cautions. “That then becomes a bit of a challenge because if the precision of the test is not great, you might have a result that may be wrong.”

Be patient and persistent if more data or additional overnight tests are needed. You may need to work with your doctor to provide documentation to your insurance plan for coverage. While a single study might be sufficient to detect sleep apnea, “studies have shown that multiple nights are preferable — but it’s difficult to get multiple nights covered,” Kushida says.

Medicare Part B and private insurance plans typically cover sleep studies if they’re considered “medically necessary,” Abbasi-Feinberg says. “If no one complains about something, you can’t just order a sleep study. But if somebody comes in with reason to have a sleep study, and the documentation is there, then insurance usually covers it,” Abbasi-Feinberg says.

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Michael Schroeder is a freelance health writer and editor who's covered everything from chronic disease and mental health to medication side effects. His stories have been published in a range of print and digital publications, including Time, U.S. News & World Report, The Washington Post, and Psychology Today.