What is CPAP therapy and how does it work?

Sleep apnea treatment Nov, 15 2024

CPAP therapy benefits, possible side effects and how the therapy works.

CPAP*, or continuous positive airway pressure, is a therapy that enables people with breathing problems, such as obstructive sleep apnea (OSA) and chronic snoring, to breathe more easily as they sleep.

CPAP is considered to be a leading treatment for people with OSA. The American Academy of Sleep Medicine (AASM) refers to it as being the OSA treatment of choice, and it recommends that it be a therapy option for all people with OSA.1,2

In the United States, it has been reported that 4% of men and 2% of women meet the criteria for symptomatic OSA. More recently, prevalence has been reported to be as high as 14% of men and 5% of women in the United States.6   

OSA can have serious implications on your health, family, and day-to-day activities, including your ability to work.3  Read more about the symptoms of sleep apnea here.


During CPAP therapy, the device takes in room air and blows it out at a pressure set to accommodate your individual needs. The pressure level is prescribed by a doctor. The constant air pressure keeps the airway open and obstruction free, enabling you to breathe uninterrupted during sleep. The device also tracks your therapy results.2

CPAP is not a cure for OSA, but a therapy used to treat the condition. To experience relief from your OSA, the therapy must be delivered every time you sleep – it is not a one-off solution.

It is important you take time to get to know your CPAP equipment. Ask your doctor or healthcare provider questions so you can familiarize yourself with all the parts of the device and be comfortable with how they work. 

Components of CPAP therapy

CPAP therapy comprises a mask connected to a CPAP machine via a tube.

Combined, these components treat OSA, which is a condition caused by a blockage of the airway. This condition occurs when the soft tissue in the upper airway blocks the flow of air in and out of the nose and mouth when the muscles in your throat relax during sleep. OSA can be associated with other health problems, such as high blood pressure, daytime sleepiness and stroke, and it can affect your brain activity and mood.1

What benefits does CPAP offer?

CPAP therapy is found to be very effective in keeping the airway open in people with OSA. It has been associated with the following beneficial clinical outcomes for people with sleep-disordered breathing.1,2

  • Improvement in overall sleep quality, sleep patterns and REM sleep
  • Improvement in neurocognitive functions, e.g., concentration and memory, depressive moods and quality of life.
  • Reduction in snoring.
  • Reduction in night-time waking.
  • Reduction in excessive daytime sleepiness, and improved alertness during the day.
  • Improvement in oxygenation.
  • Lowering of hypertension.
  • Improved apnea-hypopnea index (AHI) outcomes. (AHI is the measurement of sleep apnea severity.)

Are there side effects of using CPAP therapy?

Although CPAP therapy can be effective in reducing the symptoms of OSA, some issues can arrive with the constant use of the device. However, CPAP therapy is considered a safe and noninvasive method of managing OSA. It is important you remain compliant with the treatment. Inconsistency could result in worsening OSA symptoms.

Some of the common side effects of CPAP therapy are:1,4,5

  • facial skin irritation
  • dry mouth or sore throat
  • nasal congestion, including runny nose and sinus pain
  • eye irritation
  • difficulty sleeping.

These effects can be mitigated by:

  • using the CPAP device for short periods initially, and acclimatizing to the therapy
  • using padding and making sure the mask fits well
  • keeping the equipment clean
  • using a humidifier
  • using nasal saline spray.

How to pick the right CPAP machine

Your sleep clinic will help you choose the right CPAP equipment for you. 

There are several device types. Each one has different comfort and lifestyle settings. This enables you to personalize the therapy. 

Most devices offer humidification, but there is also an option of selecting a standalone humidifier that can supplement your CPAP machine.

How to pick the right CPAP mask

Your close interaction with your mask makes it one of the most important components of your CPAP therapy. 

However, it can be the trickiest part of the CPAP therapy setup to get right. Read more about which type of CPAP mask is right for you.

How does CPAP therapy work?

CPAP machines provide pressure by using a motor to allow room air (not oxygen) to be taken in through a filter and pressurized according to settings prescribed by your healthcare professional.1

Having a better understanding of how CPAP therapy works, including the different components of the system and the technology behind it, may help to improve your results of CPAP therapy. Read more about how CPAP therapy works.

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