Snooze University

What Happens in a Sleep Study? (For Sleep Apnea, Insomnia, etc.)

by Dale Cudmore | Updated: Jan 17, 2022

Sleep studies are a vital tool in either investigating sleep problems, or confirming the diagnosis of a sleep condition.

They involve professionals monitoring your sleep with appropriate equipment in a controlled setting in order to gather reliable data.

Let’s go through what to expect during a sleep study to ease any nerves or concerns you may have about them.

When is a Sleep Study Needed?

Sleep studies are used when sleep apnea, narcolepsy, periodic limb movement disorders, or certain types of insomnia are suspected.

Signs of these sleep conditions that may prompt a primary care physician to refer you to a sleep study include:

  • Snoring
  • Constant fatigue
  • Abnormal sleep movements
  • Randomly falling asleep during the day
  • Family history of sleep conditions

Types of Sleep Studies

There are 2 main types of sleep studies:

  • Polysomnograms - These are the most common. They are overnight sleep studies that involve a single standard sleep period.
  • MSLTs - These are daytime sleep studies mostly used to diagnose whether or not someone has narcolepsy. They usually consist of 5 separate nap periods at 2 hour intervals during the day.

What to Do The Day Before a Sleep Study

Before an overnight sleep study, it’s important to:

  • Not consume caffeine (e.g. from coffee, tea, or chocolate)
  • Don’t take naps
  • Take medications as usual unless directed otherwise by your doctor

There’s no need to stress about it or do anything else that you wouldn’t usually do.

Even if you can’t get to sleep quickly during a sleep study, valuable data can still be collected, so there’s no pressure.

What to Bring to a Sleep Study

You’ll usually be told to bring anything you’ll need to a sleep study, but in general it’s a good idea to bring:

  • Pajamas of some kind
  • Personal toiletries (although these are often provided)
  • Any medications you need
  • Change of clothes for the next day

You won’t be provided food at an overnight sleep study, so it’s typically best to eat dinner before you go.

On the other hand, food is provided during daytime sleep studies.

What Happens During a Sleep Study?

Once you arrive for a sleep study, you’ll fill out some registration paperwork and be shown to a room that usually resembles a small hotel room.

This room is monitored by healthcare professionals like sleep technologists and respiratory therapists.

When they are ready, they will place electrodes on your head, face, nose, chest, abdomen, and legs. These are painless, and are attached with a small adhesive.

Note that no electronic devices can be used in bed, and partners are not allowed either.

While trying to go to sleep, you are typically allowed to read or do a limited number of other activities. From this time period on, data will be collected on your:

  • Brain waves
  • Breathing
  • Movement
  • Oxygen levels
  • Heart rate

This is enough to diagnose most sleep issues.

And if you need to get up or go to the bathroom, you can just let an attendant know (there’s a microphone in the room to hear you).

What Happens After a Sleep Study?

Once you wake up, you can get ready for the day and leave unless you need to do a daytime study as well.

The results do take 1-2 weeks to analyze and send to your primary care physician (whoever referred you).

They will then be able to walk you through any next steps to be taken or a treatment plan.

You will typically get a copy of your results, which typically includes things like number of apneas, and PLMS index score.

Can I Do a Sleep Study at Home?

You can buy home sleep study kits at a fraction of the price of an in-lab sleep study and are obviously more convenient. However, these are typically only good for certain issues (e.g. apnea, not insomnia or narcolepsy), and are less reliable than an in-lab study.

They are often covered by insurance, as they are prescribed tests (you can’t get them over the counter).

What if I Can't Sleep During a Sleep Study

While it's common to be nervous about not being able to sleep during a sleep study, most people do end up being able to get to sleep.

It's typically a fairly comfortable setting, and the minimum sleep time that's needed to collect useful isn't that high.

You can ask about sleeping medication before-hand to see if it's allowed. It varies based on testing location.

Even if you can't sleep right away, you can read or do other relaxing things until you fall asleep.

Finally, in the absolutely worst case scenario that you can't sleep at all, it's not the end of the world. A new study can always be scheduled. In addition, the fact that someone can't fall asleep may reveal some information about why they're having issues in the first place.

Medical Disclaimer: The information on is not intended to be a substitute for physician or other qualified care. We simply aim to inform people struggling with sleep issues about the nature of their condition and/or prescribed treatment.

About the authorDale is the founder of Snooze University and a sleep researcher. I overcame my sleep issues and now I'd like to help you do the same by summarizing the latest sleep studies for you.