How does CPAP therapy work?

Sleep apnea treatment Sep, 18 2024

We take a closer look how this therapy helps treat obstructive sleep apnea

CPAP* stands for continuous positive airway pressure.   

It is a leading therapy option for people with breathing conditions, such as sleep apnea and chronic snoring.   

Under this therapy, a CPAP machine delivers a constant flow of oxygenated air into your airways through a tube and CPAP mask that is sealed around the mouth or nose (or both).

This keeps your airways open so you can enjoy better sleep. 


How does CPAP air pressure work?  

Room air is taken in through a filter on your CPAP device and pressurized to settings prescribed by your healthcare professional. 1  

The pressurized air is then delivered via tubing to your mask interface and on to your upper airway. This constant flow of air creates an air cushion that prevents the airway from collapsing and helps to normalize your breathing as you sleep. 1  

CPAP machine air pressures range from 4 cmH2O (four centimetres of water) to a maximum of 30 cmH2O. This air can also be passed through a heated humidifier before it is delivered from the device and on to the airway. 1


What are the main components of a CPAP therapy system? 

CPAP therapy is used to treat sleep disorders, such as sleep apnea. The three main components of a CPAP system are: 

  • CPAP machine   
  • CPAP mask   
  • tubing.  

The CPAP machine takes in room air and pressurizes it to a prescribed setting before it is delivered through tubing to your mask. Read on for more details on these components.  


CPAP machines  

A CPAP machine is designed to sit discreetly by your bedside. It typically consists of a motor, water container, power supply, tubing to connect to the mask and a digital method of storing your sleep data, e.g., breathing patterns and pressure changes, etc.  


CPAP humidifiers 

A CPAP humidifier warms and moisturizes the air you are breathing.  

This may reduce your risk of experiencing a dry mouth or throat.2   

Humidifiers have been shown to help enhance therapy comfort levels and treatment compliance.2,3   

Most CPAP machines include an integrated or detachable humidifier.   

When humidifiers are used, heated breathing tubes may be required to maintain the temperature of the humidified air from the device to the mask. This also prevents condensation forming in the tubing.  


CPAP masks 

CPAP masks are the interfaces that receive pressurized air from your CPAP machine before it is delivered to your upper airway.

They generally consist of headgear, a tube that attaches to the CPAP machine and a cushion that seals around your nose, mouth or both. There are four mask types: Nasal pillows masks, nasal masks, full-face (oronasal) masks and oral masks. 

CPAP masks must fit and seal properly for your therapy to be successful. If they don’t, the work being done by your CPAP machine may become ineffectual and your treatment could be uncomfortable. 

Because CPAP masks have such an important role in the success of your therapy, it is worthwhile putting time and effort into ascertaining what size and type of mask best suits you. 


The content is for educational purposes only. It should not be used as a substitute for the medical advice of one’s healthcare provider.

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