CPAP, or continuous positive airway pressure, is a treatment that uses mild air pressure to keep your airways open while you sleep. CPAP is used for people who have breathing problems, such as sleep apnea.

This treatment is done using a CPAP machine. CPAP machines have three main parts:


  •  A mask or other device that fits over your nose or your nose and mouth. Straps keep the mask in place while you're wearing it.   
  •  A tube that connects the mask to the machine's motor.   
  •  A motor that blows air into the tube.  

Some CPAP machines have other features as well, such as heated humidifiers. CPAP machines are small, lightweight, and fairly quiet. The noise that they make is soft and rhythmic. Overview

CPAP is the most effective treatment for obstructive sleep apnea. Sleep apnea is a common disorder in which you have pauses in breathing or shallow breaths while you sleep. When this happens, not enough air reaches your lungs.

In obstructive sleep apnea, your airways collapse or are blocked during sleep. The blockage may cause shallow breathing or breathing pauses. When you try to breathe, any air that squeezes past the blockage can cause loud snoring. Your snoring may wake other people in the house.

The mild pressure from CPAP can prevent your airway from collapsing or becoming blocked.

The animation below shows how CPAP works. Click the "start" button to play the animation. Written and spoken explanations are provided with each frame. Use the buttons in the lower right corner to pause, restart, or replay the animation, or use the scroll bar below the buttons to move through the frames.


                             Information and animation courtesy of the National Heart, Lung and Blood Institute

The animation shows how a CPAP mask can be used to keep the airways open and prevent sleep apnea symptoms. The animation shows how a CPAP mask can be used to keep the airways open and prevent sleep apnea symptoms.

If your doctor prescribes CPAP, you will work with someone from a home equipment provider (sometimes called durable medical equipment, or DME) to select a CPAP machine.

Your doctor will work with you to make sure the settings that he or she prescribes for your CPAP machine are correct. He or she may recommend an overnight sleep study to find the correct settings for you. Your doctor will want to make sure the air pressure from the machine is just enough to keep your airways open while you sleep.

There are many different kinds of CPAP machines and masks. Be sure to tell your doctor if you're not happy with the type you're using. He or she may suggest switching to a different kind that may work better for you.


CPAP has many benefits. It can:


  •  Keep your airways open while you sleep    
  •  Correct snoring so others in your household can sleep    
  •  Improve the quality of your sleep    
  •  Relieve symptoms of sleep apnea, such as excessive daytime sleepiness    
  •  Decrease or prevent high blood pressure  

Many people who use CPAP report feeling better once they begin treatment. They feel more attentive and better able to work during the day. They also report fewer complaints from bed partners about snoring and sleep disruption.