Waking up with a mouth like sandpaper is one of the most common CPAP complaints, and one of the most common reasons people stop using their machine. The good news: it nearly always has a fixable cause.
Why it happens
- Your mouth falls open. With a nasal mask or pillows, air goes in your nose and straight out of your mouth, drying it as it goes. This is the biggest cause.
- The mask leaks. A poor seal blows air across your lips and eyes.
- The air is too dry. Without enough humidity, pressurised air dries everything it touches.
- A blocked nose pushes you to breathe through your mouth.
- Other things can add to it: some medicines (such as antihistamines and decongestants), not drinking enough, and some health conditions.
What to try
- Turn up the humidifier, or add a heated tube so the warm, moist air doesn't cool and drip before it reaches you.
- Keep your mouth closed with a chin strap.
- Switch to a mask that covers your mouth: a full face or under-nose full face mask. Our mask finder can help you pick a style.
- Fix the seal. See why your mask might be leaking.
- Treat a blocked nose: saline spray helps many people; ask your doctor about anything stronger.
What your data can show
Mouth leak shows up as leak. In CPAPGeeks, open a night and look at the leak chart: steady bursts through the night, especially with a nasal mask, often mean your mouth is opening. If those nights are also your dry-mouth mornings, you've found the cause. Watch the leak chart drop after a fix to see whether it worked.
If dryness keeps up after these changes, tell your sleep clinician. Don't put up with it: it's a common reason people give up on therapy, and it's usually solvable.