Continuous positive airway pressure therapy (CPAP) uses a machine to help a person who has obstructive sleep apnea (OSA) breathe more easily during sleep. A CPAP machine increases air pressure in your throat so that your airway doesn't collapse when you breathe in. When you use CPAP, your bed partner may sleep better too.
You use CPAP at home every night while you sleep. The CPAP machine will have one of the following:
- A mask that covers your nose and mouth.
- A mask that covers your nose only—called nasal continuous positive airway pressure, or NCPAP (this type of mask is most common).
- Prongs that fit into your nose.
What To Expect After Treatment
It may take time for you to become comfortable with using CPAP. If you can't get used to it, talk to your doctor. You might be able to try another type of mask or make other adjustments.
Why It Is Done
CPAP is the most effective non-surgical treatment for obstructive sleep apnea. It is the first treatment choice for adults and the most widely used.
How Well It Works
CPAP is effective for treating sleep apnea:
- CPAP is better than other non-surgical methods for treating obstructive sleep apnea.footnote 1
- Research shows that CPAP decreases daytime sleepiness, especially in those who have moderate to severe sleep apnea.footnote 2, footnote 3, footnote 4
- People who use CPAP for longer times each night (around 7 hours) have less daytime sleepiness and depression and fewer heart issues than people who use CPAP for shorter times (around 5 hours).footnote 5
- People with coronary artery disease who use CPAP for sleep apnea are less likely to have heart problems such as heart failure.footnote 6
- Studies show that in people who have moderate to severe sleep apnea, nasal continuous positive airway pressure (NCPAP) lowers blood pressure during both the day and the night.footnote 7, footnote 8
Problems that may occur with CPAP include:
- Excessive dreaming during early use.
- Dry nose and sore throat.
- Nasal congestion, runny nose, and sneezing.
- Irritation of the eyes and the skin on the face.
- Abdominal bloating.
- Leaks around the mask because it doesn't fit properly.
Nosebleeds are a rare complication of CPAP.
You can expect mild discomfort in the morning when you first start using CPAP. Talk with your doctor if you don't feel comfortable after a few days.
Relieving side effects
You may be able to limit or stop some of the side effects:
- If your nose is runny or congested, talk with your doctor about using decongestants or corticosteroid nasal spray medicines.
- Your doctor may be able to adjust your CPAP to reduce or eliminate problems.
- Be sure the mask or nasal prongs fit you properly. Air shouldn't leak around the mask.
- Use a humidifier or a corticosteroid nasal spray medicine to reduce nasal irritation and drainage.
- You may want to talk to your doctor about trying other types of CPAP machines.
- One type of machine will start with a low air pressure and slowly increase the air pressure as you fall asleep. This kind of machine can help reduce discomfort caused by too much constant pressure in your nose.
- A bilevel positive airway pressure machine (BiPAP) uses a different air pressure when you breathe in than when you breathe out. You may find BiPAP more comfortable than CPAP because you can breathe out against a lower air pressure. As a result, you may be more likely to continue the treatment. You will have to spend the night at a sleep laboratory to find the air pressure levels that work best for you.
- An auto-titrating continuous positive airway pressure (APAP) can automatically decrease or increase the air pressure as needed. This may make the machine more comfortable and easier to use.
What To Think About
When you are using CPAP, you need to see your doctor or sleep specialist regularly. You may also need more sleep studies to adjust the CPAP machine and check whether the treatment is working.
For best results, keep the machine clean. Follow the manufacturer's instructions for cleaning the equipment.
The machines are expensive. Check to see if your provincial health plan or private insurance covers the cost. You may be able to rent a CPAP machine before you buy it. In some cases, you may be able to rent-to-own a CPAP machine. BiPAP and APAP machines are usually more expensive than CPAP machines.
The most common problem with CPAP is that people don't use the machine every night. Or they take off the mask during the night because it becomes uncomfortable. Even one night of not using the machine can make you sleepy the next day. If you feel like you want to stop using CPAP for any reason, talk to your doctor. There may be other treatment options for you.
Health Canada has approved some brands of portable CPAP machines. You may be able to take a smaller CPAP machine on vacations or other types of trips.
- Lam B, et al. (2007). Randomised study of three non-surgical treatments in mild to moderate obstructive sleep apnoea. Thorax, 62(4): 354–359.
- Giles TL, et al. (2006). Continuous positive airways pressure for obstructive sleep apnoea in adults. Cochrane Database of Systematic Reviews (3).
- Hensley M, Ray C (2009). Sleep apnoea, search date May 2008. Online version of BMJ Clinical Evidence: http://www.clinicalevidence.com.
- Weaver TE, et al. (2012). Continuous positive airway pressure treatment of sleepy patients with milder obstructive sleep apnea: Results of the CPAP Apnea Trial North American Program (CATNAP) randomized clinical trial. American Journal of Respiratory and Critical Care Medicine, 186(7): 677–683.
- Bouloukaki I, et al. (2014). Intensive versus standard follow-up to improve continuous positive airway pressure compliance. European Respiratory Journal, 44(5): 1262–1274. DOI: 10.1183/09031936.00021314. Accessed February 5, 2015.
- Milleron O, et al. (2004). Benefits of obstructive sleep apnoea treatment in coronary artery disease: A long-term follow-up study. European Heart Journal, 25(9): 728–734.
- Barbe F, et al. (2010). Long-term effect of continuous positive airway pressure in hypertensive patients with sleep apnea. American Journal of Respiratory and Critical Care Medicine, 181(7): 718–726.
- Marin JM, et al. (2012). Association between treated and untreated obstructive sleep apnea and risk of hypertension. JAMA, 307(20): 2169–2176.
Current as of: February 24, 2020
Author: Healthwise Staff
Anne C. Poinier MD - Internal Medicine
Donald Sproule MDCM, CCFP - Family Medicine
E. Gregory Thompson MD - Internal Medicine
Adam Husney MD - Family Medicine
Mark A. Rasmus MD - Pulmonology, Critical Care Medicine, Sleep Medicine
Hasmeena Kathuria MD - Pulmonology, Critical Care Medicine, Sleep Medicine
Current as of: February 24, 2020
Author: Healthwise Staff
Medical Review:Anne C. Poinier MD - Internal Medicine & Donald Sproule MDCM, CCFP - Family Medicine & E. Gregory Thompson MD - Internal Medicine & Adam Husney MD - Family Medicine & Mark A. Rasmus MD - Pulmonology, Critical Care Medicine, Sleep Medicine & Hasmeena Kathuria MD - Pulmonology, Critical Care Medicine, Sleep Medicine