Nasal CPAP

CPAP stands for "continuous positive airway pressure." CPAP is a treatment that delivers slightly pressurized air during the breathing cycle.

This keeps the windpipe open during sleep and prevents episodes of blocked breathing in persons with obstructive sleep apnea and other breathing problems.

It is sometimes called nasal continuous positive airflow pressure (nCPAP).



Continuous positive airflow pressure (CPAP) is the best treatment for most people with obstructive sleep apnea. It is safe and effective in patients of all ages, including children. If you only have mild sleep apnea and do not feel very sleepy during the day, you may not need to use it.

After using CPAP regularly, many patients report the following:

  • Better concentration and memory
  • Feeling more alert and less sleepy during the day
  • Improved sleep for the person's bed partners
  • Improvements in work productivity
  • Less anxiety and depression and a better mood
  • Normal sleep patterns
  • Improvement in heart and blood vessel problems, such as high blood pressure

A similar machine, called BiPAP (bilevel positive airway pressure) is used as an alternative to CPAP. With this machine, the pressure changes while a person breathes in and out.

These devices are useful for children and adults with collapsible airways, small lung volumes, or muscle weakness that makes it difficult to breathe, such as muscular dystrophy.

CPAP or BiPAP may also be used by people who have:


CPAP works in the following way:

  • The device is a machine weighing about 5 pounds that fits on a bedside table.
  • A mask fits over the nose. A tube connects the mask to the CPAP device.
  • The machine delivers a steady stream of air under slight pressure through this tube into the mask.

CPAP will be started while you are in the sleep center for the night. Sometimes, it can be started on the same night you have your sleep study.

The doctor, nurse, or therapist will help choose the mask that fits you best. They will also help adjust the settings on the machine while you are asleep. The settings on the CPAP machine depend on the severity of your sleep apnea.

If you are using the CPAP machine but your sleep apnea symptoms do not improve, the settings on the machine may need to be changed. Some patients can be taught to adjust the CPAP at home. Otherwise, you will need to make trips to the sleep center.

CPAP works by steadily increasing pressure in your airway. Newer devices, called autotitrating positive airway pressure (APAP) can respond to changes in pressure in your airway as they occur. This may be more comfortable, and it also can help you avoid overnight stays and other trips to the hospital.


It can take time to become used to a CPAP device. The first few nights of CPAP therapy are often the hardest. Some patients may sleep less or not sleep well at the start of treatment.

Patients who are having problems may tend not to use CPAP for the whole night, or even stop using the device. However, it is important to use the machine for the entire night or for as long as possible.

Common complaints include:

  • A feeling of being closed in (claustrophobia)
  • Chest muscle discomfort, which usually goes away after a while
  • Eye irritation
  • Irritation and sores over the bridge of the nose
  • Nasal congestion and sore or dry mouth
  • Noise that interferes with sleep (although most machines are quiet)
  • Nosebleeds
  • Upper respiratory infections

Many of these problems can be helped or prevented by the following methods:

  • Ask your doctor or therapist about using a mask that is lightweight and cushioned. Some masks are used only around or inside the nostrils.
  • Make sure the mask fits correctly. It should not be too tight or too loose, and it should not leak any air.
  • Try nasal salt water sprays for a stuffed nose.
  • Use a humidifier to help with dry skin or nasal passages.
  • Keep your CPAP equipment clean.
  • Place your CPAP machine underneath your bed.

Your doctor or therapist can lower the pressure on the CPAP machine and then increase it again at a slow pace. Some new machines can automatically adjust to the pressure that is needed.

Alternative Names

Continuous positive airway pressure; CPAP; Bilevel positive airway pressure; BiPAP; Autotitrating positive airway pressure; APAP; nCPAP


McArdle N, Singh B, Murphy M. Continuous positive airway pressure titration for obstructive sleep apnoea: automatic versus manual titration. Thorax. 2010;65:606-611.

Tomfohr LM, Ancoli-Israel S, Loredo JS, Dimsdale JE. Effects of continuous positive airway pressure on fatigue and sleepiness in patients with obstructive sleep apnea: data from a randomized controlled trial. Sleep. 2011;34:121-126.

Basner RC. Continuous positive airway pressure for obstructive sleep apnea. N Engl J Med. 2007;356:1751-1758.

Epstein LJ, Kristo D, Strollo PJ Jr., et al.; Obstructive Sleep Apnea Task Force of the American Academy of Sleep Medicine. Clinical guideline for the evaluation, management, and long-term care of obstructive sleep apnea in adults. J Clin Sleep Med. 2009;5:263-276.

Update Date: 4/31/2012

Reviewed by: Denis Hadjiliadis, MD, Assistant Professor of Medicine, Division of Pulmonary, Allergy, and Critical Care, University of Pennsylvania, Philadelphia, PA. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

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