CPAP vs. BiPAP: Exploring Your Sleep Therapy Options
If you have sleep apnea, your doctor may recommend positive airway pressure (PAP) therapy. PAP devices push pressurized air through a tube and mask to keep your airway open while you sleep. The two most common types are CPAP and BiPAP. Both treat sleep apnea, but they work differently and are used in different situations.
How CPAP Works
CPAP stands for continuous positive airway pressure. A CPAP machine delivers the same level of air pressure when you breathe in and when you breathe out. This steady pressure keeps the airway from narrowing or collapsing during sleep.
Most CPAP machines include a motorized unit, a tube, and a mask. Many newer models also include a heated humidifier to reduce nasal dryness. CPAP is the standard first-line treatment for obstructive sleep apnea (OSA) and is effective for most people with mild to moderate OSA.
How BiPAP Works
BiPAP stands for bilevel positive airway pressure. Unlike CPAP, a BiPAP machine delivers two different pressure levels. The pressure is higher when you breathe in and lower when you breathe out. The inhale pressure is called IPAP (inspiratory positive airway pressure) and the exhale pressure is called EPAP (expiratory positive airway pressure).
This two-level approach can make it easier to breathe out against the pressure. BiPAP machines can be fixed (set pressures that do not change) or auto-adjusting (pressures that vary throughout the night based on your breathing).
BiPAP also has specialized modes. In spontaneous mode, the machine responds to your own breathing effort. In spontaneous/timed mode, the machine adds a backup breathing rate if you go too long without a breath. This is often used for people with central sleep apnea or very weak breathing.
Key Differences
The most important practical differences between CPAP and BiPAP involve pressure, cost, and who each device is best suited for.
CPAP delivers one pressure level in a range of 4 to 20 cm H2O. BiPAP covers a wider range of 4 to 30 cm H2O and provides two separate pressure settings. CPAP machines typically cost between $500 and $1,000. BiPAP machines are more expensive, ranging from $1,700 to $3,000.
Insurance usually covers CPAP for obstructive sleep apnea. BiPAP coverage may require proof that CPAP was tried first and was not effective or not tolerated.
Who Should Use CPAP
CPAP is the recommended treatment for most people with obstructive sleep apnea. It is simpler to set up and use, more affordable, and widely available. It works well for mild, moderate, and many cases of severe OSA. Doctors may also recommend CPAP for people with congestive heart failure, severe COPD, or certain other breathing conditions.
Who Should Use BiPAP
BiPAP is often recommended when CPAP is not enough or not tolerated. Specific situations where BiPAP may be preferred include:
- OSA that requires pressure levels beyond the CPAP range
- Central sleep apnea or complex sleep apnea
- Conditions that cause slow or shallow breathing during sleep, such as COPD, neuromuscular disease, or obesity hypoventilation syndrome
- People who struggle to breathe out against a fixed CPAP pressure
</ul>
Choosing the Right Option
Your doctor or sleep specialist will recommend the right device based on your sleep study results, diagnosis, and any other health conditions you have. For most people with straightforward obstructive sleep apnea, CPAP is the right starting point. If CPAP does not work well for you, BiPAP may be the next step. The goal of both therapies is the same: to keep your airway open so you breathe normally throughout the night.
Key Takeaway: CPAP and BiPAP both treat sleep apnea by delivering pressurized air to keep your airway open. CPAP uses one steady pressure level and is the standard first treatment for most people with obstructive sleep apnea. BiPAP uses two pressure levels and is better suited for people who cannot tolerate CPAP, need higher pressures, or have more complex breathing conditions. Your doctor will help determine which device is right for you.
Think you might have sleep apnea?
Take our free 5-minute assessment and find out your risk level.
Take the Free Assessment