Using BiPAP Therapy to Treat Sleep Apnea

Bilevel positive airway pressure (BiPAP) is a breathing treatment for sleep apnea and other health conditions that impact breathing. This treatment is less common than continuous positive airway pressure (CPAP). However, in some situations, it is more beneficial.

For example, where CPAP provides consistent air pressure, BiPAP offers varying pressure. BiPAP's difference in air pressure can be helpful for people who have trouble exhaling against CPAP's continuous pressure.

This article explains how BiPAP is used to treat obstructive sleep apnea and central sleep apnea.

Man sleeping with BiPAP mask on his face
cherrybeans / Getty Images

What Is BiPAP or Bilevel Therapy?

Much of a BiPAP machine is the same as the standard CPAP machine. For example, it still requires a face mask and tubing connected to the device. But there are some differences between BiPAP and CPAP.

The pressurized air settings of the BiPAP include:

  • Inspiratory positive airway pressure (IPAP): This is the pressure the machine provides as you inhale. The BiPAP provides a higher IPAP than the CPAP. So, when you inhale, the BiPAP supports your breath as you take it in.
  • Expiratory positive airway pressure (EPAP): This is the pressure the machine provides when you exhale. The BiPAP offers a lower pressure that allows you to breathe out comfortably.

These pressures are preset based on your doctor's prescription. They alternate just like your breathing pattern.

Beyond these standard settings, there are a few other available variations. They include:

  • Bilevel ST: This includes the timed delivery of a breath if the machine detects a pause in your breathing. These pauses often occur in central sleep apnea.
  • Auto or adaptive servo-ventilation (ASV): These advanced settings vary the timing, length, and volume of the breaths the machine delivers. 


The key distinguishing feature of BiPAP is that it delivers pressurized air at two different levels. While CPAP provides the same level of consistent air pressure, BiPAP offers more air pressure when you inhale and less pressure when you exhale.


Click Play to Learn About BiPAP

This video has been medically reviewed by Sanja Jelic, MD.

When BiPAP Therapy Is Used

BiPAP is breathing support that treats central sleep apnea. The cause of this condition is now always known, but it is sometimes seen in people who have:

Doctors may also prescribe it in more severe obstructive sleep apnea. BiPAP is beneficial when mixed apnea events are present, suggesting a component of central sleep apnea.


BiPAP is more expensive than a standard CPAP machine. It may be two or three times the cost of a CPAP. The ASV models can cost more than $4,000.

In addition to treating central sleep apnea, BiPAP is also helpful in the following situations:

  • People who have trouble with CPAP: People who have difficulty breathing out against CPAP pressure may benefit from BiPAP. People more commonly have problems with CPAP when higher pressures are required to keep the airway open. For example, at pressures higher than 15 centimeters of water pressure (CWP), BiPAP may help to improve compliance among those struggling with CPAP therapy.
  • People who are hospitalized: BiPAP is a non-invasive treatment for people who are in respiratory distress but who do not wish to be on a ventilator.
  • People with neuromuscular disease: It may be helpful in those with conditions that cause nerve and muscle weakness, such as amyotrophic lateral sclerosis (ALS).


BiPAP is most often used to treat central sleep apnea. But, doctors may also prescribe it when someone does not tolerate CPAP well and when someone needs breathing support but doesn't want to be on a ventilator.

BiPAP, Bilevel, and VPAP

There is some confusion about the word BiPAP, bilevel, and VPAP. They are all essentially the same thing. However, the names of the device vary somewhat based on the manufacturer. They include:

  • Respironics: One of the major manufacturers of these devices, Respironics, has registered BiPAP as a trademark name for the technology generically called bilevel.
  • ResMed: The other major competitor, ResMed, calls similar devices VPAP (variable positive airway pressure).
  • AirCurve: ResMed also markets AirCurve that is a bilevel device. 

Though the names may be different, the basic principles are the same.


In most cases of obstructive sleep apnea, CPAP alone is sufficient as a therapy. However, BiPAP may be a good alternative in the more complicated scenarios or when it is difficult to tolerate CPAP.

A Word From Verywell

BiPAP is an alternative to CPAP to treat those with central sleep apnea. In addition, those who cannot tolerate CPAP and those hospitalized with respiratory distress who do not wish to be on a ventilator may opt for BiPAP.

If you wonder whether BiPAP would be appropriate for you, start by speaking with your sleep doctor. After they evaluate your risk factors and sleep study, they can recommend the proper treatment.

Frequently Asked Questions

  • What is the difference between BiPAP and a ventilator?

    Bilevel positive airway pressure (BiPAP) is a type of ventilator that is used to treat sleep apnea and other conditions in which a person is still able to breathe on their own but assistance is needed. BiPAP is referred to as a positive pressure ventilator. This is because a person using a BiPAP machine will receive positive air pressure when they breathe in and out, but the air pressure is higher when they breathe in.

  • What is ALS?

    Amyotrophic lateral sclerosis (ALS) is a disease that attacks the motor neurons that control our muscles. Over time, ALS causes muscles to weaken, and can eventually cause a person to be unable to move their arms, legs, mouth, or entire body. This can affect their ability to breathe, which means a ventilator such as a BiPAP machine may be needed to help with breathing.

  • What is a VPAP?

    Variable positive airway pressure (VPAP) machines are ventilators that are similar to a BiPAP machine. The VPAP is produced by a company called ResMed, while the BiPAP is manufactured by the company Respironics. Both machines work to achieve a similar result.

Was this page helpful?
1 Source
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Johns Hopkins Medicine. BiPap.

Additional Reading