When you buy through our links, we may earn a commission. Products or services may be offered by an affiliated entity. Learn more.

/ CPAP: Continuous Positive Airway Pressure

What Is a CPAP Machine?

Updated April 29, 2024

Fact-Checked

The Sleep Foundation editorial team is dedicated to providing content that meets the highest standards for accuracy and objectivity. Our editors and medical experts rigorously evaluate every article and guide to ensure the information is factual, up-to-date, and free of bias.

The Sleep Foundation fact-checking guidelines are as follows:

We only cite reputable sources when researching our guides and articles. These include peer-reviewed journals, government reports, academic and medical associations, and interviews with credentialed medical experts and practitioners.
All scientific data and information must be backed up by at least one reputable source. Each guide and article includes a comprehensive bibliography with full citations and links to the original sources.
Some guides and articles feature links to other relevant Sleep Foundation pages. These internal links are intended to improve ease of navigation across the site, and are never used as original sources for scientific data or information.
A member of our medical expert team provides a final review of the content and sources cited for every guide, article, and product review concerning medical- and health-related topics. Inaccurate or unverifiable information will be removed prior to publication.
Plagiarism is never tolerated. Writers and editors caught stealing content or improperly citing sources are immediately terminated, and we will work to rectify the situation with the original publisher(s)
Although Sleep Foundation maintains affiliate partnerships with brands and e-commerce portals, these relationships never have any bearing on our product reviews or recommendations. Read our full Advertising Disclosure for more information.

Up-to-Date

Table of Contents

How Does a CPAP Machine Work?
What Is a CPAP Machine Used For?
Common Issues With CPAP
How Do I Know If I Need a CPAP Machine?
Frequently Asked Questions

If you or your bed partner have undiagnosed or untreated obstructive sleep apnea (OSA), getting a good night’s sleep might feel impossible. The good news is that OSA symptoms, including snoring and low-quality sleep, usually improve and sometimes disappear with regular use of a medical device called a continuous positive airway pressure (CPAP) machine.

How Does a CPAP Machine Work?

CPAP machines use pressurized air to keep a person’s airway open. These devices usually have three main components.

Machine: CPAP machines contain a settings display, motor that generates pressurized air, and often a heated humidifier chamber. Depending on the model, devices may be as small as a brick or as large as a shoe box.
Tube: CPAP machines deliver filtered, pressurized air taken from the room through a flexible plastic tube that is usually 6, 8, or 10 feet long.
Mask: The tube connects to a mask that sits beneath the nose, fits over the nose, or seals around the nose and mouth. The mask is generally secured by adjustable straps.

There are several kinds of positive airway pressure (PAP) devices, but CPAP machines — which pump air at a continuous, customized pressure setting throughout the night — are typically the first treatment choice Trusted Source UpToDate More than 2 million healthcare providers around the world choose UpToDate to help make appropriate care decisions and drive better health outcomes. UpToDate delivers evidence-based clinical decision support that is clear, actionable, and rich with real-world insights. View Source for people with moderate to severe obstructive sleep apnea.

Suspect You May Have Sleep Apnea?

Answer three questions to understand if you should be concerned.

Snore loudly?

Tired during the day?

Wake up short of breath?

What Is a CPAP Machine Used For?

By delivering pressurized air through the nostrils or the mouth, CPAP machines help prevent apneas and hypopneas—disruptions in breathing caused by collapsing or narrowing of the soft tissues in the nose and throat. Unlike some forms of mechanical ventilation, CPAP devices do not breathe for a person. Instead, CPAP users must breathe on their own, and as they do so, pressurized air from the machine acts as a stent Trusted Source UpToDate More than 2 million healthcare providers around the world choose UpToDate to help make appropriate care decisions and drive better health outcomes. UpToDate delivers evidence-based clinical decision support that is clear, actionable, and rich with real-world insights. View Source to keep relaxed muscles and tissues from collapsing into the airway.

“People using CPAP therapy can breathe normally during sleep, with normal oxygen levels and better sleep quality since their airway is protected. CPAP therapy eliminates snoring and may reduce restlessness during sleep.”

Dr. Audrey Wells

Sleep Medicine Physician, CPAP Expert , MD

CPAP therapy is the gold standard treatment for obstructive sleep apnea. Research shows that treating OSA with CPAP therapy has many benefits. Day-to-day benefits include less sleepiness, clear thinking, and reduced appetite. Long-term benefits Trusted Source Medline Plus MedlinePlus is an online health information resource for patients and their families and friends. View Source include reduced risk of heart diseases, diabetes, and dementia. Additionally, users also often experience:

Normal breathing during sleep, with normal blood oxygen levels
Improved blood pressure
No snoring
Increased alertness during the day
Enhanced ability to focus and retain information
Higher productivity

When used consistently, CPAP therapy is typically more effective than other OSA treatment options. The more severe your sleep apnea symptoms are, the more likely you are to benefit from using a CPAP machine.

While CPAP therapy is most commonly used to treat obstructive sleep apnea, it is also sometimes used to treat breathing-related problems Trusted Source UpToDate More than 2 million healthcare providers around the world choose UpToDate to help make appropriate care decisions and drive better health outcomes. UpToDate delivers evidence-based clinical decision support that is clear, actionable, and rich with real-world insights. View Source caused by heart failure, respiratory failure, and obesity. For those that need supplemental oxygen, an oxygen concentrator can be added to the CPAP tubing through the use of an oxygen tubing adapter.

Common Issues With CPAP

Some people find that using a CPAP machine is challenging or uncomfortable, especially in the beginning. Some of the most commonly reported issues are:

Mask discomfort
Air leaks
Dry mouth
Dryness or irritation of the nose
Bloating causes by swallowed air

Many people find CPAP therapy more tolerable after an initial period of adjustment. Acclimation to CPAP treatment normally includes trying different mask types or sizes to get the fit right. Using a high quality mask that fits well and sleeping on a specially designed pillow can also alleviate some of the difficulties of using a CPAP machine.

There are also ways to reduce the discomfort that can accompany CPAP use, including using nasal sprays, making changes to the humidifier setting, and practicing during the day so you can make adjustments when there is no pressure to sleep.

How Do I Know If I Need a CPAP Machine?

A medical provider can help you determine if you are a candidate for CPAP therapy. It’s important to talk to your doctor if you — or your bed partner — suspect that you have obstructive sleep apnea, as early treatment can help prevent long-term health problems. Symptoms of OSA include:

Daytime sleepiness
Snoring
Pauses in breathing followed by gasps during sleep
Feeling unrefreshed upon waking
Difficulty paying attention or remembering information
Morning headaches

In order to determine the severity of your OSA and the appropriateness of CPAP therapy as a treatment, your doctor will likely ask you to participate in an overnight sleep study in a laboratory. You may also be able to confirm the diagnosis of OSA using an at-home sleep apnea test.

Are There Alternatives to a CPAP Machine?

Doctors sometimes recommend other kinds of positive airway pressure devices to people who don’t improve with CPAP therapy or who find it very uncomfortable. These include auto-adjusting PAP (APAP) machines, which change air pressure depending on the needs of the sleeper, and bilevel PAP (BPAP) machines, which alter air pressure during inhalation and exhalation. Additional treatments that can help manage symptoms include:

Wearing an oral appliance designed to keep your airway open
Sleeping on your side
Losing weight
Avoiding alcohol and smoking
Surgical treatments

“CPAP alternatives are not always effective. For this reason, confirmatory testing is recommended to determine if OSA is still present.”

Dr. Audrey Wells

Sleep Medicine Physician, CPAP Expert , MD

Frequently Asked Questions

How long does it take a CPAP machine to work?

For many, using a CPAP machine immediately reduces snoring, improves sleep quality, and decreases daytime sleepiness. However, some of the benefits of CPAP therapy, such as reduced blood pressure, take more time.

Do I need to use my CPAP machine all night?

If you want to effectively treat your OSA, you should use your CPAP machine every time you sleep and for the whole time you are in bed. Many individuals with sleep apnea have worsening of the condition during REM sleep. Most REM sleep naturally occurs in the second half of the night. Lack of muscle tone is a feature of REM sleep, so supportive air pressure from a CPAP machine is especially beneficial during REM periods to ensure normal breathing.

How much does a CPAP machine cost?

CPAP machine prices range from $500 to more than $1,000. However, with a documented OSA diagnosis, most insurance providers cover the cost of CPAP machines and related supplies.

Still have questions? Ask our community!

Join our Sleep Care Community — a trusted hub of product specialists, sleep health professionals, and people just like you. Whether you’re searching for the perfect mattress or need expert sleep advice, we’ve got you covered. Get personalized guidance from the experts who know sleep best.

Written By

Lucy Bryan, Contributing Writer

Lucy Bryan is a writer and editor with more than a decade of experience in higher education. She holds a B. A. in journalism from the University of North Carolina at Chapel Hill and an M.F.A. in creative writing from Penn State University.

Medically Reviewed by

Dr. Audrey Wells, Sleep Medicine Physician, CPAP Expert MD

Audrey Wells, MD attended University of Michigan Medical School and went on to train at Washington University School of Medicine in pediatrics and pediatric pulmonary medicine. It was during this time that she developed a specific interest in adult and pediatric sleep medicine. She returned to her home state of New Mexico to complete a sleep medicine fellowship.

Learn more about our Editorial Team

References
4 Sources

Malhotra, A. (2024, Feb 08). Obstructive sleep apnea: Overview of management in adults. In N. Collop & G. Finlay (Ed.). UpToDate.
https://www.uptodate.com/contents/obstructive-sleep-apnea-overview-of-management-in-adults
Strohl, K. (2024, Jan). Patient education: Sleep apnea in adults (Beyond the basics). In N. Collop & G. Finlay (Ed.). UpToDate.
https://www.uptodate.com/contents/sleep-apnea-in-adults-beyond-the-basics
A.D.A.M. Medical Encyclopedia. (2023, April 20). Positive airway pressure treatment. MedlinePlus.
https://medlineplus.gov/ency/article/001916.htm
Hyzy, R. & McSparron, J. (2024, Jan). Noninvasive ventilation in adults with acute respiratory failure: Practical aspects of initiation. In P. Parsons & G. Finlay (Ed.). UpToDate.
https://www.uptodate.com/contents/noninvasive-ventilation-in-adults-with-acute-respiratory-failure-practical-aspects-of-initiation