Comfort and side effects
CPAP Bloating and Gas (Aerophagia): Causes and Fixes
Waking up bloated, burping or gassy on CPAP is called aerophagia, which means pressurized air went into your stomach instead of your lungs. NHLBI says to stop using your PAP and contact your provider if you have stomach discomfort or bloating, because the fixes (pressure changes, APAP, mask changes) go through your clinician.
Signs
- Bloated or tight belly on waking
- Burping or belching in the morning
- Passing a lot of gas
- Stomach pain or gurgling
- Reflux or heartburn
Common causes
- Air entering the esophagus
- The Sleep Foundation explains that during sleep, relaxed muscles can let pressurized air slip into the esophagus and travel to the stomach.
- Pressure level
- F&P notes pressure set too high can push air into the esophagus, while pressure set too low can leave you gulping air. Only your clinician can judge which applies to you.
- Mask type and mouth breathing
- An editorial on a randomized trial reported aerophagia was greater with oronasal (full face) fixed CPAP than with nasal fixed CPAP. F&P also notes mouth breathers can get aerophagia with nasal masks.
- Being new to CPAP
- The Sleep Foundation says symptoms are most common early in treatment.
Fixes to try, easiest first
Contact your provider before your next night with your clinician
NHLBI says that if you have stomach discomfort or bloating, you should stop using your PAP machine and contact your healthcare provider. Call your sleep doctor or equipment provider and describe what is happening.
Avoid extra swallowed air in the evening
Cut back on fizzy drinks, chewing gum and drinking through straws before bed, and eat slowly. These are common causes of swallowed air.
Check for mouth leak
If you use a nasal mask and breathe through your mouth, F&P suggests considering a chinstrap or a different mask style.
Ask about pressure and auto CPAP with your clinician
In a randomized crossover study discussed in a JCSM editorial, auto CPAP lowered median pressure from 14 to 9.8 cm H2O and significantly improved aerophagia symptoms. Your clinician decides whether a pressure change or APAP mode is right for you.
Ask about a nasal mask instead of full face with your clinician
The same editorial reported more aerophagia with full face masks than nasal masks. Ask your provider whether a nasal mask is an option for you.
Ask about bilevel therapy with your clinician
The Sleep Foundation lists BiPAP, which uses lower pressure when you breathe out, as a treatment option your clinician may consider.
Contact your provider whenever CPAP gives you stomach discomfort or bloating, as NHLBI advises. Get urgent care for severe belly pain, a hard swollen belly, vomiting, or trouble breathing. Persistent reflux or heartburn is also worth raising with your doctor.
Supplies that can help
A soft strap that supports the jaw to help keep the mouth closed, used mainly with nasal and nasal pillow masks to reduce mouth leaks.
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Mask types this applies to
Frequently asked questions
Why do I burp so much after using CPAP?
Air from the machine can slip into your esophagus and stomach during sleep, which you then burp or pass as gas. It is called aerophagia and is common, especially early on.
How common is CPAP aerophagia?
The Sleep Foundation estimates 16% to 50% of CPAP users have aerophagia symptoms.
Can I just turn my pressure down to stop bloating?
No. Lowering pressure on your own can let your apneas come back. Your clinician can review your data and decide whether a pressure change, APAP or a different mask is right.
Does sleeping position help aerophagia?
Some people find sleeping with the head raised or on their side helps, and the Sleep Foundation lists lying on your back as one cause of air swallowing. Ask your provider what is right for you.
Sources
Last reviewed October 11, 2026. How we research · Report an error