What is a BiPAP machine?

BiPAP, or bilevel positive airway pressure, is a machine that provides two pressure settings: a higher one for inhaling and a lower one for exhaling. The lower exhale pressure makes breathing out feel less like working against a wall, which some people find more comfortable than CPAP.

How is BiPAP different from CPAP?

CPAP delivers one constant pressure for both inhaling and exhaling. BiPAP delivers two: higher in, lower out. That difference matters most at higher pressures and for people who struggle to exhale against CPAP, or who have certain heart or lung conditions.

Who needs a BiPAP instead of a CPAP?

BiPAP is often used for people who need high pressures, cannot tolerate exhaling against CPAP, or have conditions like certain forms of central sleep apnea or respiratory disease. It is prescribed by a clinician, not chosen off a shelf, because the right setting depends on your diagnosis.

BiPAP Machines Explained: How They Work

People often search for BiPAP as if it were a completely different kind of machine, when it is really another flavor of the same idea: keep the airway open with air pressure. What sets it apart is that it stops asking you to breathe out against a steady wall of air, and for some people that single change is the difference between tolerable and not.

What BiPAP is

BiPAP stands for bilevel positive airway pressure. Like CPAP, it pushes pressurized air through a mask to splint the airway open. Unlike CPAP, it uses two pressure levels: a higher inspiratory pressure when you breathe in and a lower expiratory pressure when you breathe out.

What it does differently

The two-level design targets the most common CPAP complaint at higher pressures, which is the effort of exhaling. With CPAP, you breathe out against the same pressure you breathe in against. BiPAP drops the pressure on exhale, so breathing out feels more natural. The machine senses your breathing and switches between the two levels automatically.

Who it helps most

BiPAP tends to come up for people who need high pressures that feel like too much to exhale against on CPAP, people who simply cannot get comfortable with fixed pressure, and people with certain conditions beyond ordinary obstructive sleep apnea, including some forms of central sleep apnea and respiratory disease. It is a prescribed device, and the settings depend entirely on your diagnosis. In Canada, as in the United States, BiPAP machines generally require a prescription from a doctor or sleep clinician; accessories may be easier to buy separately, but machine type and settings are not a DIY choice.

Common problems

BiPAP shares the usual positive-airway-pressure issues: mask fit, leaks, and dryness, all covered in CPAP mask leaks and CPAP humidifiers. It is also more expensive than CPAP and is not automatically more effective for straightforward obstructive apnea, so it is not an upgrade everyone needs.

How it compares to CPAP and APAP

The short version: CPAP is one fixed pressure, APAP adjusts a single pressure automatically within a range, and BiPAP uses two distinct pressures for in and out. The full comparisons are in CPAP vs BiPAP and APAP vs CPAP vs BiPAP.

When to talk to a clinician

BiPAP is not something to request because it sounds fancier. If you are on CPAP and struggling specifically with exhaling, or you have been told you need high pressures, that is the conversation to have. A new beginner should start with the beginner’s guide to CPAP equipment.

This is general information, not medical advice. Machine type and settings are prescribed based on your sleep study. See the equipment hub for the full lineup.