What Does CPAP Stand For?

Key Takeaways

• CPAP stands for continuous positive airway pressure and delivers a single, consistent level of air pressure.
• BPAP or BiPAP stands for bilevel positive airway pressure and provides two different pressure settings: one for inhaling and a lower one for exhaling.
• APAP stands for automatic positive airway pressure and automatically adjust the air pressure based on your breathing patterns.

What Is CPAP Therapy?

CPAP is a type of positive airway pressure (PAP), which treats obstructive sleep apnea (OSA) by delivering pressurized air through a face mask while you sleep. The goal of this treatment is to keep open the airway that leads to your lungs, preventing air flow obstructions that are characteristic of sleep apnea.

These are the three main types of PAP therapy:

Continuous Positive Airway Pressure (CPAP)

CPAP therapy is the most common type of PAP therapy. Like all types of PAP therapy, CPAP machines continuously deliver air through a mask to prevent airway blockages. Typically, CPAP machines deliver air at a fixed pressure level throughout the night. 

A CPAP machine’s fixed pressure level is selected based on the results of an overnight PAP titration study, during which different pressure settings are tested during sleep and the lowest effective pressure is selected.

Pressure needs to be just high enough to maintain healthy breathing during moments when the airway would otherwise get blocked. The pressure level can be changed again in the future if needed, but the machine can only provide one constant pressure setting at a time.

Bilevel Positive Airway Pressure (BiPAP or BPAP)

Unlike fixed-level CPAP, BiPAP machines alternate between two different pressure levels:

• Inspiratory PAP (IPAP), the air pressure during the sleeper’s inhale 
• Expiratory PAP (EPAP), the air pressure during the sleeper’s exhale 

Generally, BiPAP is set up to provide higher air pressure when inhaling than exhaling, which some people may find more comfortable than a constant pressure level. The machine senses whether the person is inhaling or exhaling, responding with the appropriate pressure level. 

Automatic Positive Airway Pressure (APAP)

APAP machines don't rely on fixed pressure levels. Instead, they operate at a range of pressure levels, automatically adjusting within this range to meet the sleeper’s needs.

Sensors pick up on the APAP user’s breathing patterns and use algorithms to match the pressure level accordingly. If someone’s breathing starts to slow or pause, the machine responds with increased air pressure to correct the issue. 

Both CPAP and BiPAP can be equipped with auto-adjusting technology. This added tech may make the experience more comfortable for the sleeper by only supplying higher pressure air when it’s most needed.

Other Types of PAP Therapy

While CPAP, BiPAP, and APAP are the most commonly prescribed forms of positive airway pressure therapy, a few specialized options are used in certain situations. These therapies are typically recommended for people with specific breathing disorders or those who do not respond well to standard PAP treatments.

• Expiratory Positive Airway Pressure (EPAP): EPAP devices use small, disposable valves placed over the nostrils to create resistance as you exhale. This back pressure helps keep the airway open without requiring a machine or tubing.
• Adaptive Servo-Ventilation (ASV): ASV machines use an advanced form of PAP therapy that continuously monitors breathing patterns and adjusts pressure levels on a breath-by-breath basis to stabilize breathing and prevent pauses.
• KairosPAP (KPAP): KairosPAP is a newer, experimental PAP therapy that adjusts air pressure dynamically throughout the breathing cycle, rather than delivering a constant pressure like CPAP.

Don’t Just Test Your Sleep. Understand It.

Measure key sleep metrics and review your results with a licensed sleep-care provider. Discuss sleep issues and options to make restless nights a thing of the past.

Results and data from the comfort of your own bed

Virtual consultation with a licensed sleep-care provider

Diagnosis, prescription, and personalized care plan

4.8

35,000+ tests sold

Get Started

What Are the Benefits of CPAP Therapy?

CPAP therapy is currently the best treatment available for sleep apnea, providing many benefits when used regularly:

• Better sleep quality 
• Less snoring 
• Improved mental health 
• Better daytime alertness 
• Improved blood pressure 
• Improved quality of life 
• Reduced risk of car accidents, stroke, and heart and lung complications 

Another advantage of PAP machines is the ability to adjust the treatment to meet personal needs and preferences. The variety of types of PAP machines, features, and masks allows people to find the right fit for them to achieve healthy and comfortable sleep.

How Do You Choose the Right Type of PAP Therapy?

Choosing the right type of PAP therapy depends on your sleep apnea diagnosis, your comfort needs, and how well you tolerate different pressure settings. Most people start with CPAP, since it’s the standard treatment for OSA and works well for mild to severe cases. If you're struggling to stay consistent with CPAP, your sleep specialist may recommend BiPAP or APAP.

Your doctor will consider factors like your apnea-hypopnea index (AHI), overall health, nighttime symptoms, and comfort during a CPAP trial to determine the best match. Because comfort plays a major role in long-term adherence, working closely with a sleep specialist and being open about any side effects or challenges can help you find the PAP therapy that delivers consistent, restful sleep.