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

When you first start using a CPAP machine, it’s supposed to help you breathe better at night. But for many people, it ends up causing more problems than it solves. Dry mouth. Air leaking out of your mask. Pressure that feels too high or too low. These aren’t just annoyances-they can make you quit therapy altogether. And if you stop using your CPAP, your sleep apnea comes back, and with it, the fatigue, the snoring, the high blood pressure, the risk of heart problems. The good news? Most of these issues have simple, proven fixes. You don’t need to buy a new machine or give up. You just need to know where to look.

Dry Mouth: It’s Not the Humidifier’s Fault

You turn on your CPAP, and by morning, your mouth is so dry it feels like you’ve been chewing sandpaper. You assume the humidifier isn’t working right. So you crank it up to max. Still dry. That’s because dry mouth from CPAP isn’t usually caused by dry air-it’s caused by mouth breathing. When your mouth opens during sleep, the pressurized air escapes through it instead of staying in your airway. That airflow dries out your mucous membranes. Studies show 42% of CPAP users deal with this, and nearly two-thirds of them are mouth breathers.

Here’s what actually works: First, check if you’re breathing through your mouth. Do you wake up with your lips parted? Does your mask have a wet spot on the chin? If yes, you’re a mouth breather. The fix isn’t more humidity-it’s keeping your mouth closed. A chin strap is the cheapest and most effective solution. Used by 38% of mouth breathers, it gently holds your jaw in place without being uncomfortable. Some users switch to a full-face mask, which covers both nose and mouth. One Reddit user reported his dry mouth vanished within three nights after switching. He didn’t change his humidifier. He just stopped breathing through his mouth.

If you still want to tweak the humidifier, set it to level 3 or 4 on a 0-6 scale. Too high (level 5 or 6) can cause condensation in the tubing-known as rainout-which makes the machine louder and can leak water onto your face. Heated tubing helps too. Philips’ 2022 trial showed it reduces dry mouth by 32%. But again, if you’re breathing through your mouth, no amount of heat will fix it.

Mask Leaks: The Silent Therapy Killer

Leaking air doesn’t just wake you up with a hissing sound. It also means your therapy isn’t working. Dr. David White from Harvard says leaks over 24 L/min seriously reduce effectiveness. You might think your mask is sealed because it doesn’t fall off. But leaks can be tiny-just enough to drop your pressure and let apneas sneak back in.

Most leaks come from three places: the cushion, the straps, or the mask size. If your mask is old, the cushion may have cracked or lost its seal. Replace it every 3 months. That’s not a suggestion-it’s what 92% of DME providers recommend. If the cushion is new, check the straps. Too tight? It digs into your skin and creates new leak points. Too loose? Air escapes around the edges. The right fit is subtle. Try this: Turn on the machine, lie down, and slowly adjust each strap until the hissing quiets. You should hear a soft, steady airflow-not a whistle or a puff. This is called the airflow test. Most people need 3-5 adjustments to get it right.

Headgear matters too. If you toss and turn, your mask shifts. Look for masks with adjustable headgear that wraps around the back of your head, not just over your ears. Some users swear by the ResMed AirFit F30i, which has minimal contact and stays put even if you sleep on your side. Others find that switching from a nasal pillow to a nasal mask reduces leaks by 40%. The key? Don’t guess. Test. Adjust. Repeat.

Pressure Adjustments: Don’t Guess, Don’t Ignore

You got your CPAP set to 12 cm H₂O. It felt fine at first. Now, months later, you feel like you’re fighting the air. Or maybe you wake up gasping. That’s not normal. Pressure isn’t a one-time setting. Your body changes. Weight fluctuates. Nasal congestion comes and goes. Your pressure needs to change too.

Auto-adjusting CPAPs (called APAP) do this automatically. Models like the ResMed AirSense 11 and Philips DreamStation 2 monitor your breathing every 5-10 seconds and tweak pressure on the fly. But even these aren’t perfect. If your pressure is stuck too high, it can cause chest discomfort, dryness, or even aerophagia (swallowing air). One user on Reddit had his pressure set at 14 cm H₂O. He felt pressure in his chest. After his sleep specialist dropped it to 9 cm H₂O and turned on expiratory pressure relief (EPR), he slept like a baby.

Dr. Nancy Collop from Johns Hopkins says pressure below 5 cm H₂O can still be effective for many people. That’s lower than most think. You don’t need to be at max pressure to stop apneas. In fact, over-titration is a problem. Dr. Barry Krakow points out that 35% of poor outcomes come from focusing too much on pressure and not enough on mask fit. If your mask leaks, no amount of pressure will help. Fix the leak first.

Never adjust pressure yourself beyond ±2 cm H₂O. That voids your warranty. Talk to your provider. Most modern machines track your data. Look at your sleep report. Are you having more than 5 events per hour? Is your leak rate above 20 L/min? If yes, your pressure might be off. Your sleep specialist can remotely review your data and adjust settings without you leaving home-especially now that Medicare covers telehealth CPAP management as of January 2024.

What You Can Do Right Now

You don’t need to wait for an appointment. Start here:

1. Check your mask cushion. If it’s older than 3 months, replace it.
2. Use a chin strap if you wake up with a dry mouth.
3. Set your humidifier to level 3 or 4. Use heated tubing if you have it.
4. Do the airflow test: adjust straps until the hissing stops.
5. Look at your machine’s data. Is your leak rate above 24 L/min? Are you having more than 5 apneas per hour? If yes, call your provider.

Most people fix these issues within two weeks. ResMed’s own data shows 78% of users master basic troubleshooting in 14 days. You’re not alone. Over 142,000 people on Reddit’s r/CPAP share tips every day. The goal isn’t perfection-it’s consistency. You don’t need to sleep 8 hours perfectly. You just need to use your machine 4+ hours a night, 5+ nights a week. That’s the threshold Medicare uses to keep covering your device.

When to Call a Professional

Some problems need more than a DIY fix. If you’ve tried everything and still have:

• Chronic dry mouth despite a chin strap and humidifier
• Leaks that won’t seal after replacing the cushion and adjusting straps
• Pressure that feels too high or too low even after trying auto-adjust
• Waking up with headaches, ear pain, or sinus pressure

Then it’s time to see your sleep specialist. You might need a different mask type, a different machine, or a re-titration sleep study. Some people do better with a BiPAP instead of CPAP, especially if they need higher pressure or have lung issues. Others benefit from nasal dilators or positional therapy. But none of that matters if you’re not using your machine. The biggest threat to your health isn’t your CPAP-it’s quitting.

What’s Next for CPAP Therapy

The technology is getting smarter. ResMed’s upcoming S+ algorithm, launching in Q2 2024, promises 23% better leak compensation. Philips’ DreamMapper app already gives personalized pressure tips based on 30 days of usage. By 2027, nearly half of all CPAPs will connect to smartwatches and send alerts if you’re not sleeping well. But none of that helps if you’re not using your machine. The real breakthrough isn’t in the machine-it’s in you. Fix the leaks. Stop the mouth breathing. Adjust the pressure with help. Keep using it. That’s how you get your sleep back.