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Sleep Study

  • A noninvasive test that electronically records activity in the brain and body during sleep
  • For diagnosing sleep-related conditions such as insomnia, restless legs, and sleep apnea
  • The next step could be to determine a treatment, which can range from melatonin to a CPAP machine
  • Involves sleep medicine program, asthma & airways disease program

Sleep Study


“I feel so rested!” When was the last time you heard someone say those words? Chances are that it’s been a while. As many as 50 to 70 million adults in the United States have a chronic sleep disorder, and many others struggle with sleep-related issues for which they haven’t seen a doctor.

At Yale Medicine, our specialists in the Sleep Medicine Program conduct comprehensive studies for people who suspect they may have a sleep disorder, and use the results to craft an individualized treatment program.

Most sleep disorders respond well to treatment but failing to get the treatment you need can cause a cascade of physical, mental and emotional health problems. “If left untreated, sleep disorders can result in abnormal mental function and behaviors,” says Christine Won, MD, director of Yale Medicine’s Women’s Sleep Health Program.

How can I tell if I should have a sleep study?

If you have trouble falling asleep, staying asleep, or often don’t feel rested, even when you first wake up in the morning, you should talk to your doctor about undergoing a sleep study. Sleep is vital to good health and the average adult should get 7-9 hours of sleep a night. If you aren’t getting enough sleep, or if your sleep is of poor quality, you are at higher risk for hypertension, heart disease, stroke, depression, diabetes, and other chronic diseases. That’s in addition to the exhaustion and cognitive difficulties everyone links with poor quality sleep.

Here are some common signs that indicate a person may have a sleep disorder:

  • Difficulty falling asleep or staying asleep
  • Excessive snoring or gasping for breath when sleeping
  • Experiencing tingling, creeping, itching, pulling, aching, and other strange feelings in your legs while sitting or lying down
  • Feeling extreme fatigue during the day that persists for more than 2 weeks

What is it like to have a sleep study?

Our sleep studies are conducted at sleep labs at Yale New Haven Hospital, with locations in North Haven and Madison. Each patient spends the night in a hotel-like “bedroom,” comfortably furnished and even equipped with a television so that you can be comfortable. 

Upon your evening arrival, you’ll spend about an hour being hooked up to the monitors, including having small electrodes to your head, face, chest and legs to measure brain and muscle activity. A clear plastic tube will also be placed near your nose to measure breathing activity. While these devices may seem intrusive, most patients don’t find it difficult to get an adequate amount of sleep during a sleep study.

You can also opt to conduct the test at home with a kit that will measure breathing abnormalities. However, this version of the test is less sensitive and may only pick up on very severe sleep apnea. If the findings are positive (meaning, you show signs of having a sleep disorder) you may need to come to the lab for a sleep study anyway.

What kinds of tests do Yale Medicine doctors run in a sleep study?

The medical name for a sleep study is a electrocardiogram (EKG). It incorporates multiple tests, all of which will occur throughout the night while you sleep.  These tests include:

  • An electrocardiogram (EKG) to monitor your heart rate, in order to detect any abnormal heart rhythms. 
  • Electromyography (EMG) which monitors muscle movement and can track REM sleep, restless leg syndrome or other muscle movements during sleep.
  • An electroencephalogram (EEG) to measure sleep stages or look for abnormal brain activity like seizures during sleep.
  • A breathing test to look for respiratory abnormalities during sleep, including chest and abdominal movements, and airflow through mouth and nose, which can help doctors diagnose sleep apnea.

Your doctor may also run a multiple sleep latency test (MSLT), which tests how quickly a person falls asleep to measure how sleepy you are during the day. Or the doctor may use a maintenance of wakefulness (MWT) test, which measures a person’s ability to stay awake under conditions that would usually cause sleepiness. These tests help doctors diagnose narcolepsy. 

What kinds of underlying sleep disorders do doctors look for through a sleep study?

  • Sleep apnea, characterized by loud snoring with gaps in between. People with this condition where the person stop breathing intermittently throughout the night.
  • Nocturnal epilepsy, in which the patient has seizures during the night
  • Restless leg syndrome, a disorder characterized by unpleasant sensations in the legs, particularly at night
  • Narcolepsy, a sleep disorder that causes excessive daytime drowsiness and often makes people fall asleep unexpectedly during the day
  • Insomnia, or difficulty falling and/or staying asleep
  • Parasomnia, a category of abnormal behaviors that occur while sleeping, including sleepwalking and sleep eating.

Treatment options for sleep disorders vary based on your diagnosis and include a wide range of alternatives. Many patients can be helped by such treatments as cognitive behavioral therapy aimed at changing sleep habits, or treatments such as melatonin, light therapy or medication. A small percentage of patients require surgery to correct physiological problems that may be at the root of their sleep difficulties, while others benefit from the use of a device called a continuous positive airway pressure (CPAP) machine. 

Does Yale Medicine conduct sleep studies for children?

For children, our Pediatric Sleep Medicine Program offers overnight sleep studies at Yale New Haven Children’s Hospital and at Bridgeport Hospital. The cheerfully decorated are dedicated to evaluating children, and also include a separate bed so a parent or guardian can also spend the night in the room.

 “Our technical staff is very experienced at dealing with the needs of children, which are different than the needs of adults who are having sleep studies,” says Yale Medicine’s Craig A. Canapari, MD, medical director of the pediatric program. 

The pediatric sleep center staff has special expertise in working with children who have anxiety and/or developmental disabilities. We take special care to ensure that children feel comfortable with the monitoring equipment, which is similar to what is used for adults. We also offer home sleep testing equipment and daytime monitoring devices to evaluate narcolepsy and other conditions. Our program is the only one in Connecticut with physicians board-certified in pediatric sleep medicine.

How is Yale Medicine’s sleep team different from sleep program in other places?

At Yale Medicine, our sleep team is focused on providing comprehensive care for people with sleep disorders. A sleep study is just the beginning. Once the study results are available, our doctors will work with you to develop a plan to improve your sleep

Our positive airways pressure (PAP) management program trains patients on how to use their CPAP machine (this is a device to improve airflow during sleep). Because of our program, 80% of our patients who are prescribed CPAP actually use the machine; this is double the national average of 40%.

Our sleep team also includes psychologists to help you with any anxiety related to your sleep or to the use of new sleep-related devices. We provide follow-up care for many of our patients for the rest of their lives. In addition to caring for adults, our sleep program is the only one in Connecticut with physicians who are board-certified in pediatric sleep medicine.

The clinicians on our sleep team are at the forefront of research on cardiovascular and stroke complications of sleep apnea. Our physicians showed that sleep apnea is linked to stroke and diabetes, and how appropriate treatment can lower the risk.

“Treating sleep disorders is not just taking a pill,” says Dr. Won. “It’s about comprehensive, long-term care.”