If you’ve ever struggled with persistent fatigue, loud snoring, or difficulty staying asleep, your doctor might recommend a sleep study. But what exactly is a sleep study, and what can you expect if you need one? Let’s break it down so you feel prepared and informed.

What Is a Sleep Study?

A sleep study, or polysomnography, is a non-invasive test that monitors your body while you sleep. It measures brain activity, breathing patterns, heart rate, oxygen levels, and muscle movements to help diagnose sleep disorders. Sleep studies are commonly used to detect conditions like:

• Sleep apnea – A condition where breathing repeatedly stops and starts during sleep.
• Restless leg syndrome (RLS) – An uncontrollable urge to move your legs, often disrupting sleep.
• Insomnia – Chronic difficulty falling or staying asleep.
• Narcolepsy – A disorder causing excessive daytime sleepiness and sudden sleep attacks.
• Periodic limb movement disorder (PLMD) – Repetitive, involuntary leg movements during sleep.

Types of Sleep Studies

There are several types of sleep studies tailored to specific conditions:

• Nocturnal Polysomnogram (NPSG): The standard overnight test that evaluates a wide range of disorders, including sleep apnea and periodic limb movements.
• CPAP Titration: Focused on finding the right air pressure to treat obstructive sleep apnea.
• Split Study: Combines diagnostic and therapeutic testing in one night for severe cases of sleep apnea.
• Multiple Sleep Latency Test (MSLT): Measures daytime sleepiness to diagnose narcolepsy.

Your doctor will determine which type is most appropriate based on your symptoms.

What Happens During a Sleep Study?

A sleep study can take place in a sleep lab or at home, depending on your symptoms and doctor’s recommendation. Here’s what happens in each setting:

In-Lab Sleep Study

If your doctor orders a full polysomnography, you’ll spend a night at a sleep center. When you arrive at the sleep center, you’ll be guided to a private room resembling a hotel room. Technicians will attach sensors to your body to monitor various functions while you sleep. Don’t worry — these wires are gathered behind your head so you can move freely in bed.

These sensors track your:

• Brain waves (EEG) to monitor sleep stages.
• Eye movement (EOG) to assess REM (rapid eye movement) sleep.
• Breathing patterns and oxygen levels to detect sleep apnea.
• Heart rate and rhythm (ECG) to monitor cardiovascular function.
• Limb movements to check for restless leg syndrome or periodic limb movements.

Some studies also involve video monitoring to observe unusual movements or behaviors during sleep. Throughout the night, a technician will observe your sleep and may adjust the sensors. If obstructive sleep apnea is detected, you may be fitted with a continuous positive airway pressure (CPAP) mask mid-study to test its effectiveness.

In the morning, technicians will remove the equipment, and you’ll be free to go home unless additional daytime tests are scheduled.

Home Sleep Apnea Test (HSAT)

For some patients, a home sleep test may be an option, primarily to diagnose sleep apnea. This test involves wearing a small device that tracks breathing patterns, oxygen levels, and airflow while you sleep in your own bed. Home sleep tests are convenient but may not capture as much data as an in-lab study.

Who Needs a Sleep Study?

Your doctor may recommend a sleep study if you experience symptoms such as:

• Loud snoring or gasping for air at night.
• Excessive daytime sleepiness despite getting a full night’s rest.
• Unexplained morning headaches or dry mouth.
• Difficulty staying asleep or waking up frequently.
• Uncontrolled leg movements that disrupt your sleep.

Certain risk factors, like obesity, high blood pressure, and a family history of sleep disorders, can also increase your likelihood of needing a sleep study.

What to Expect After Your Sleep Study

Once your study is complete, a sleep specialist will analyze the data and provide a diagnosis. They’ll look at metrics like total sleep time, stages of sleep (REM vs. non-REM), and any abnormalities detected.

These findings will guide treatment recommendations tailored to your needs — whether it’s CPAP therapy for apnea, medications for restless leg syndrome or narcolepsy, or cognitive behavioral therapy and/or lifestyle changes for insomnia.

How to Schedule a Sleep Study

If you suspect you have a sleep disorder, talk to your doctor. They will evaluate your symptoms and refer you to a sleep specialist if needed. Many sleep studies are covered by insurance, especially if you have documented symptoms of sleep apnea or another condition.

The Bottom Line

A sleep study is a valuable tool in diagnosing and treating sleep disorders that may be affecting your quality of life. If you’re experiencing persistent sleep issues, don’t ignore them — getting tested could be the first step toward better rest and better health.

Sources:

• "Your Sleep Study." American Sleep Medicine, 8 Apr. 2025, www.americansleepmedicine.com/your-sleep-study/. Accessed 8 Apr. 2025.
• Shrivastava, Deepak et al. “How to interpret the results of a sleep study.” Journal of community hospital internal medicine perspectives vol. 4,5 24983. 25 Nov. 2014, doi:10.3402/jchimp.v4.24983