Here’s an under-the-covers look at who qualifies, what to expect, and the conditions and treatment plans a sleep study might reveal.

Chances are, if you’ve ever struggled to fall asleep or stay asleep, you’ve likely consulted Dr. Google about your zzz habits.

Perhaps you’ve asked the internet whether it’s normal to keep waking up at 3 a.m. for no reason, even though you were able to fall asleep just fine.

Maybe you’ve wondered whether other people toss and turn as much as you do or whether there’s actually something clinically wrong with your sleep patterns. 

Or possibly, in the blurry haze of a middle-of-the-night internet deep dive, you’ve stumbled upon the advice to get checked out in an overnight sleep facility and wondered: What even are those, really? What actually happens if you go to one? Are they scary? Are they weird? Is it creepy to know that someone is watching you while you sleep? Are they the right solution for you? 

There are 120 different kinds of sleep-wake disorders, and the Centers for Disease Control and Prevention (CDC) also reports that one-third of U.S. adults usually get less sleep than is recommended. 

With this in mind, we checked in with three top sleep experts around the country to find out everything you need to know about sleep facilities. Consider this your A-to-zzz guide.

How one qualifies for a sleep study 

There are a few steps you need to take before you go to a sleep facility, if your doctor even recommends that you go to one at all.  

Recognizing that you have a sleep issue that could benefit from medical intervention is the first step in this process. All of the doctors we spoke with said the key to figuring that out is to look at your daily activity: Are you impacted by your previous night’s sleep during the day? 

“If your lack of sleep is not something that affects what you’re doing during the daytime, then it is probably OK,” says Hussam Al-Sharif, MD, a sleep medicine specialist at the Mayo Clinic Health System in Wisconsin. 

“But when your sleep troubles start to have an effect on your work, your relationships, your activities, and/or your quality of life, then it’s time to think about seeking advice to see what’s going on.”

Once you recognize that you have a sleep issue, the next step is to see your primary doctor, who will then refer you to a sleep specialist (also a doctor). That sleep specialist will ask you a series of general questions to pinpoint what services you may or may not need. 

“We look at all sorts of factors, beginning with a patient’s medical history, occupation (especially if they work night shifts), and sleep habits (bedtime, wakeup time, sleep environment, anything their partners have told them about their nighttime behavior),” explains Al-Sharif. 

After that, they go into your daytime habits:

  • How sleepy do you feel during the day?
  • Does this impact your work performance, and in what ways?

And finally, the sleep specialists gather what they call objective data:

  • How likely are you to doze off while reading or watching TV?
  • How much alcohol and caffeine do you drink during the day?
  • Are you currently taking any medications or supplements that interfere with sleep? 

“Once we have gathered all this information, we decide if their issue can be solved by changing their sleep hygiene [i.e., good sleep habits], or if they need further testing,” Al-Sharif continues.

If you have insomnia, for example, you likely don’t need further sleep testing, as it’s already clear that you don’t sleep — so your doctor may refer you to an insomnia specialist (a sleep doctor with a specialty in psychology) who can help you figure out what may be keeping you up. 

Getting tested

If your sleep specialist decides that you would benefit from a sleep study, also known as a sleep test, they’ll recommend one of two methods: an at-home study or an in-lab study at a sleep facility.

(FYI: Sleep facilities used to be called sleep centers or sleep clinics, but now they’re referred to as facilities, as per the American Academy of Sleep Medicine.)  

More often than not, they’ll recommend an at-home test if they believe you have sleep apnea, a common and serious condition that affects your breathing, or restless leg syndrome, a condition that causes an uncontrollable urge for you to move your legs.

Both of these conditions are able to be detected by an at-home test, so the logic is: Why do an in-lab test if you don’t need to? 

The at-home test itself is fairly simple. It’s basically a monitor that measures your oxygen and breathing levels through several different components:

  • two belts that wrap around your chest and abs to measure movements associated with breathing
  • a small device called a pulse oximeter that goes on your finger to measure how much oxygen is in your blood
  • a small tube called a breathing sensor that goes in your nostrils and behind your ears to analyze your breathing patterns

Unfortunately, oximeter numbers are generally not as accurate for Black people, as the numbers are harder to detect — but health scholars and activists are currently working to change that.

“It’s a simple system, and patients pick up on how to use it pretty quickly: You turn it on at night, turn it off in the morning, and then bring it back to the sleep center,” explains Michael Friedman, MD, FACS, medical director at Chicago ENT. 

If the data collected was invalid because of technical issues that happened overnight (dislodgement of the finger probe is a big one there), you may be asked to do the test again.

Or, if your home test showed that your sleep apnea is severe and you experienced a significant drop in oxygen levels during the night, you may be asked to take an in-lab study after all. This will help you figure out the appropriate positive air pressure device that needs to be used. 

Pack your pajamas

If your doctor suggests you come in for an in-lab overnight sleep study, fret not: It’s not as daunting as you may think. 

“In the past, sleep tests used to take place in a hospital bed, so it was essentially torture, as no one wants to go into a hospital. But modern-day sleep labs are different — they’re comfortable now,” Friedman says.

In fact, he even likens them to hotel rooms, citing their comfortable beds, lack of noise or visual clutter, and dark ambiance with blackout shades. There’s often a bathroom attached if you need to get up in the night, too. 

Most sleep labs also have simple snacks and drinks like crackers, peanut butter, bottled water, and noncaffeinated soft drinks to help you fall asleep. There are TVs and small cameras in the room, too, as the technician may watch you on video throughout the night.

But for all those who hear this and get creeped out: Keep in mind they aren’t observing you through a window or anything, so you won’t ever see them when you’re in bed.

And while there aren’t any fancy white noise machines or aromatherapy stations in a sleep lab, you’re encouraged to bring your own devices or sleep machines if you want. Generally speaking, whatever you need to do to fall asleep is fine and won’t disrupt the study. 

Behind the scenes

Now, what actually happens during this whole process?

When you arrive at the sleep lab, the sleep technician on site will give you information about what’s to come and what you can expect from this process. Usually, a sleep technician will be the one in the lab who collects the data, and then a sleep specialist will analyze the data after the fact. 

After the briefing from the technician, they’ll have you change into your sleep clothes (most people come with PJs or scrubs), and then they’ll paste 12 to 14 patches called electrodes to different locations on your body:

  • your chest to monitor cardiac activity
  • your legs to monitor leg movement
  • your scalp and forehead to monitor brainwave activity

These electrodes are attached with wires, all of which lead to a control box that’s about the size of a smartphone, which is attached to the front of your scrubs. That means that if you get up, you can disconnect the control box so you don’t have to walk with it, but everything else stays in place.

Some technicians may also set you up with some belts around your chest and abs, and a tube under your nose to measure the flow of air, depending on the circumstance. 

And then, once you’re all rigged up… it’s bedtime!

The technicians usually start the study around the time you report going to bed, so the hope is that you fall asleep like you do at home. Most patients tend to watch something on TV to help them fall asleep.

Technicians also ask you to sleep in whatever position you sleep at home, though if they notice that you’re sleeping on your back and not getting any sleep in that position, they’ll ask you to sleep on your side instead — because sleep apnea is generally worse when you’re facing up. 

“So yes, it’s not the most comfortable sleep with all the wires, but you can turn,” says Friedman. “It’s a bit restrictive, but it’s not terrible.”

Plus, key fact: The study doesn’t last all night. Once you do fall asleep, the technicians only need about 3 to 4 hours to measure your sleep, not the full 8 hours — though you can sleep for however long you want. 

“Most patients end up sleeping for about 5 to 7 hours, and leaving early in the morning, around 6 a.m., so they can actually sleep at home if they weren’t able to get a full night’s rest during the study,” explains Romulo Cordero, director of the Sleep Center and Neurodiagnostics at Crystal Run Healthcare, a health center with locations throughout New York. 

On the off chance that you get stage fright and simply can’t sleep a wink during your entire sleep study, the doctors will likely ask you to come back for another session — this time with a sleep aid.

“There’s a well-known phenomenon called the ‘First Night Effect’ where people might have decreased sleep time when sleeping in a new environment — so if that happens during the study, we’ll have to repeat it,” explains Al-Sharif.  

Finding the answers

If all goes well, your doctor will be able to diagnose you with a condition based on your sleep study, and you’ll be that much closer to a treatment plan. 

As we already mentioned, there are 120 sleep disorders in total that a sleep study can pick up on, though there are five major ones it helps to know about, explains Cordero: 

Sleep apnea

This is a disorder of the airway, and it’s very common: An estimated that 26 percent of Americans between 30 and 70 experience it. The signs include:

  • snoring
  • gasping for air or stopping breathing while you’re sleeping
  • always feeling sleepy
  • not being able to watch TV because you fall asleep so quickly

There are two types: obstructive sleep apnea (OSA), where the airway collapses due to a blockage behind the tongue, and the less common central sleep apnea (CSA), where the brain essentially stops your breathing.

The treatment involves using a CPAP machine, which helps deliver a stream of oxygenated air to your airways. 

Insomnia

You likely already know this condition: It’s when you can’t sleep. Around 30 percent of U.S. adults are diagnosed with insomnia, which can either be chronic or transient. The treatment depends on the root cause.

“We have to go deep and ask: What’s triggering this?” says Cordero. Most of the time, it’s anxiety or a psychological issue, in which case the treatment is targeted toward that disorder, but it could be lots of other things, too, like poor sleep hygiene or underlying medical problems.

If all else fails, doctors may prescribe chronic insomniacs with cognitive behavioral therapy (CBT) or pharmacotherapy (medications/hypnotics).  

Restless leg syndrome

Over 3 million people in the United States may experience restless leg syndrome, which is when you have to move your legs before falling asleep. It’s characterized by an unpleasant sensation in the legs that causes you to shake them for relief. The treatment is medication. 

REM sleep behavior disorder

This rare disorder, which affects about less than 1 percent of adults, is when you’re active during REM (dream stage) sleep when you shouldn’t be. It could be an indication of future Alzheimer’s or Parkinson’s disease. For this disorder, a neuro specialist helps with treatment. 

Narcolepsy

This disorder affects between 135,000 and 200,000 people in the United States. It’s characterized by falling asleep unexpectedly and oftentimes inappropriately, like during conversations or meetings at work. For this reason, those with it are usually not allowed to drive. It’s treated with a combination of drugs and prescribed naps. 

The other kind of sleep study

There are also sleep studies in which researchers study your sleep habits in a clinic overnight and then publish their findings. 

For that kind of study, sleep scientists usually ask for volunteers in newspaper advertisements, TV commercials, or via word of mouth — and then bring them into a special lab for testing. And while the sleep studies that you do for your own health are pretty standardized, the ones done for research purposes vary a lot more. 

They’re usually conducted in the same clean rooms with the snacks and the wires, but there’s also monetary exchange. Cordero says he’s heard of volunteers making anywhere from $20 to $3,000 simply for participating. 

Many of the research studies are done to simply figure out how normal sleep looks in terms of the stages and the duration.

Other studies may look at the effect of sleep on certain hormones or the physiological changes that happen during sleep (to your heart rate or your blood pressure, for instance), or examine sleep issues, like the ones above, in order to understand them better. 

Still, other studies might look at the result of certain interventions on sleep, explains Al-Sharif, like the effect of shift work on sleep, the effect of medications and hypnotics, or even sleep habits in certain populations. 

No matter which kind of sleep study you’re doing, though, it’s important to remember that you’re doing this for a good cause: better sleep — and therefore better overall health — for all.

After all, taking action often leads to answers, and answers often lead to new treatments, and new treatments lead to better sleep and better mental well-being.