CPAP vs. BiPAP — What's the Difference

A CPAP (Continuous Positive Airway Pressure) machine delivers a steady, constant stream of pressurized air through a mask. This pressure acts like a splint to keep your airway open while you sleep. It is the primary treatment for obstructive sleep apnea, a condition where your throat muscles collapse and block breathing. You set the machine to one specific pressure level that stays the same all night.

A BiPAP (Bilevel Positive Airway Pressure) machine provides two different pressure levels. It delivers higher pressure when you inhale and lower pressure when you exhale. This makes it easier for you to breathe out against the machine's force. Doctors typically prescribe these for patients who cannot tolerate the constant pressure of a CPAP or those with more complex respiratory issues.

CPAP is usually the first choice for standard sleep apnea because it is simpler and highly effective. If you have trouble breathing out against the fixed pressure, or if you have conditions like COPD (Chronic Obstructive Pulmonary Disease), a doctor will likely switch you to BiPAP. This machine mimics a more natural breathing pattern. It gives your lungs more support during the exhalation phase.

Because BiPAP handles two pressures, it is technically more complex to set up. Most people find the lower exhale pressure of a BiPAP more comfortable if they are struggling to adjust to equipment. However, the machines themselves look nearly identical and use similar masks and hoses. Your healthcare team will decide which pressure settings you need based on a sleep study or your specific lung health.

These machines are expensive, and navigating insurance coverage for them is often frustrating. Insurance companies usually require a formal diagnosis and a documented trial period before they pay for the equipment. Always ask your provider for a breakdown of your out-of-pocket costs before you commit to a specific model. You are entitled to clear information about your rental or purchase agreement.