CPAP Troubleshooting Guide: Fix Dry Mouth, Mask Leaks, and Pressure Issues

Why Your CPAP Isn’t Working (And How to Fix It)

You bought the CPAP machine. You followed the instructions. You’re using it every night. But you still wake up with a dry throat, your mask keeps leaking air, and the pressure feels like it’s crushing your chest. You’re not alone. Nearly half of CPAP users struggle with these exact problems - not because the machine is broken, but because the setup isn’t right for your body.

CPAP therapy is the most effective treatment for obstructive sleep apnea, cutting apnea events by 70-90% when used correctly. But if you’re dealing with dry mouth, leaks, or pressure that feels too high or too low, you’re not getting the full benefit. The good news? Most of these issues can be fixed without replacing your machine or giving up on therapy.

Dry Mouth? It’s Probably Not the Humidifier

Most people assume dry mouth means their humidifier isn’t working hard enough. So they crank the heat up to 6 or 7. That often makes things worse. The real culprit? Mouth breathing.

When you breathe through your mouth during sleep, the air from the CPAP doesn’t get warmed or moistened by your nasal passages. It rushes straight into your throat, pulling moisture out of your mouth and tongue. Studies show 42% of CPAP users experience dry mouth - and 67% of them are mouth breathers, according to user data from Reddit’s r/CPAP community.

Here’s what actually works:

• Switch to a full-face mask. These cover both your nose and mouth, so even if you open your mouth, the air stays contained. One user reported dry mouth vanished within three nights after switching.
• Use a chin strap. This simple nylon strap holds your jaw closed. It’s cheap, non-invasive, and used by 45% of mouth breathers who fix their leaks this way.
• Set your humidifier to level 3 or 4 (on a 0-6 scale). Too much heat causes condensation in the tube (rainout), which can drip and make you feel wetter, not drier. Level 3-4 hits the sweet spot for most climates, including Adelaide’s dry winters.
• Try heated tubing. ResMed and Philips both offer heated tubes that keep air warm all the way to your mask. Philips’ 2022 trial showed a 32% reduction in dry mouth with heated tubing alone.

Don’t just turn up the heat. Fix the root cause: mouth breathing.

Mask Leaks: It’s Not Always the Mask

Your CPAP machine beeps. The app shows a leak warning. You tighten the straps. The leak gets worse. You’re not doing anything wrong - you’re just chasing the wrong thing.

Mask leaks happen for three main reasons: wrong size, worn-out cushion, or poor headgear fit. The average user replaces their mask cushion every 3 months - but 72% of people wait until it’s cracked or visibly damaged. That’s too late.

Here’s how to fix leaks for good:

• Do the airflow test. With your CPAP running, gently adjust the headgear straps one at a time. Listen for the hiss. Stop when the noise drops. Most people need 3-5 small adjustments to get it right.
• Replace the cushion every 3 months. Even if it looks fine, silicone breaks down from oils in your skin. ResMed and Philips both recommend this timeline. A $30 cushion replacement can save you from $1,200 in lost therapy.
• Check your headgear. Straps stretch over time. If you’ve had your mask for over a year, the headgear might be loose even if the cushion is new. Order a replacement headgear set - they’re usually under $50.
• Don’t over-tighten. Tightening straps too much creates pressure points that make your skin swell. That causes new leaks. Aim for a seal that’s snug but doesn’t leave red marks.

Leak rates above 24 liters per minute (L/min) reduce treatment effectiveness, according to Harvard sleep expert Dr. David White. If your machine shows leaks over that, don’t ignore it. Adjust, replace, or get help.

Pressure Too High? Too Low? Don’t Guess - Adjust Smartly

Pressure settings are the most misunderstood part of CPAP therapy. Many users think higher pressure = better results. That’s not true. Too much pressure causes discomfort, dry mouth, and even aerophagia (swallowing air), which leads to bloating and gas.

Dr. Nancy Collop from Johns Hopkins says pressure adjustments below 5 cm H₂O can dramatically improve comfort without hurting effectiveness. One Reddit user, u/ExhaustedEngineer, had his pressure set at 14 cm H₂O - causing chest pain and insomnia. After his sleep specialist dropped it to 9 cm H₂O and turned on expiratory pressure relief (EPR), he slept through the night for the first time in years.

Auto-CPAP (APAP) machines like the ResMed AirSense 11 and Philips DreamStation 2 adjust pressure automatically. But they’re not magic. They need good data to work right.

• Use the machine’s built-in data. The AirSense 11 tracks your pressure needs every night. Log into your ResMed app and check your 30-day average. If it’s consistently hitting the max (say, 15 cm H₂O), your starting pressure might be too low.
• Don’t adjust pressure yourself. Most manufacturers void warranties if you override the settings beyond ±2 cm H₂O. Talk to your sleep specialist. They can re-titrate your pressure based on your actual sleep data.
• Try EPR or C-Flex. These features lower pressure slightly when you exhale. It feels like breathing out into a gentle breeze. Most users report better comfort with EPR enabled, even if their pressure stays the same.
• Watch for pressure spikes. If your machine shows sudden pressure jumps during sleep, it might be reacting to leaks or snoring. Fix the leak first - then check if pressure still spikes.

Pressure isn’t about power. It’s about precision. The right pressure is the lowest setting that keeps your airway open.

What You’re Probably Missing: Maintenance and Timing

CPAP machines are medical devices - not gadgets. They need care.

• Change your filter every 30 days. Foam filters trap dust and allergens. If you skip this, you’re breathing in particles that irritate your nose and throat.
• Wash your mask and tubing weekly. Soap and warm water. No bleach. Let everything air dry. Mold in your tubing? That’s a real risk. One user reported sinus infections after not cleaning his tubing for 6 months.
• Don’t skip the acclimation period. It takes 2-4 weeks to get used to CPAP. Your brain needs time to adjust to the airflow. Most people who quit do so before day 14. Stick with it. 78% of users master basic fixes within two weeks.

Also, don’t wait until you’re miserable to call your provider. ResMed offers 24/7 support with a 97% same-day response rate. Smaller DME providers? You might wait 2-3 days. If your machine is under warranty, use the manufacturer’s support. They’ve seen your exact issue before.

When to Seek Help - And When to Consider Alternatives

CPAP works for 85% of people with moderate to severe sleep apnea. But if you’ve tried everything - new mask, chin strap, humidifier settings, pressure tweaks - and you’re still miserable, it’s time to talk about alternatives.

• Oral appliances work for mild to moderate OSA. They’re less effective for severe cases, but 45-55% of users stick with them long-term because they’re more comfortable.
• Hypoglossal nerve stimulation (like Inspire) is a surgical implant for severe apnea. It costs $30,000-$40,000 and isn’t covered by Medicare unless you’ve failed CPAP. But for some, it’s life-changing.
• Positional therapy helps if you only apnea when you sleep on your back. A simple pillow or tennis ball sewn into your pajama back can help.

But don’t give up on CPAP too soon. The FDA says 31% of Medicare patients quit within a year - but 80% of those who stick with it for 6 months become long-term users. Your first month is the hardest. Your sixth month? You’ll forget you ever wore a mask.

Final Tip: Use Your Data

Your CPAP machine isn’t just a treatment device. It’s a data logger. Every night, it records:

• Leak rate
• Pressure used
• Hours worn
• AHI (apnea-hypopnea index)

Check it weekly. If your AHI is above 5, your therapy isn’t working well. If your leak rate is over 24 L/min, fix your mask. If you’re only using it 3 hours a night, you’re not getting the health benefits. Medicare requires 4+ hours per night for continued coverage - and your body needs it too.

CPAP isn’t perfect. But it’s the most proven, most effective tool we have for sleep apnea. The problems aren’t with the machine - they’re with the fit. Fix the fit, and you’ll sleep better than you have in years.