Dry mouth
Very commonWhy it happens
Breathing through your mouth while asleep (the pressurized air escapes through it), or no humidifier. A nasal mask makes it worse because it does not cover the mouth.
Solutions
- → Turn on or turn up the heated humidifier built into your CPAP
- → Wear a chin strap to keep your mouth closed
- → Switch to a full face mask (it covers your nose AND your mouth)
- → Check the mask for leaks
- → Drink a glass of water before bed
Remember: Dry mouth is one of the most common reasons people give up on CPAP. Tell your provider: there is almost always a fix.
Aerophagia (swallowing air: gas, bloating, burping)
CommonWhy it happens
Pressurized air is swallowed instead of breathed in. Pressure that is too high, mouth breathing or lying completely flat all make it more likely. The air builds up in your stomach and causes bloating, gas and burping when you wake.
Solutions
- → See your doctor to have the pressure reassessed (it is often too high)
- → Switch to an auto-CPAP (APAP), which adjusts the pressure in real time
- → Raise the head of the bed slightly
- → Turn on EPR or C-Flex (lower pressure when you breathe out)
- → Avoid a heavy meal in the 2 hours before bed
Remember: Aerophagia is often a sign that your CPAP pressure is not set right. Have your data reviewed.
Red marks and skin irritation
CommonWhy it happens
Too much mask pressure on the skin of your nose, cheeks or forehead. A mask that is too tight squeezes the small blood vessels and leaves red marks, even sores if nothing is done.
Solutions
- → Loosen the straps: the mask should stay in place without being tight (test: slide a finger under the strap)
- → Use fabric or gel liners (Gecko Nasal Pad, RemZzzs...)
- → Try another type of mask (nasal pillows, nasal or full face, depending on your face)
- → Try a different cushion size (S/M/L)
- → Apply a soothing cream in the morning (aloe vera, calendula)
Remember: A mask that still leaves marks an hour after you wake up is too tight. Never fix a leak by tightening: change the mask instead.
Allergy and skin reactions to the mask
UncommonWhy it happens
An allergy to the silicone or plastics of the mask. It shows up as persistent redness, itching, eczema or hives where the mask touches: not the same thing as ordinary pressure marks.
Solutions
- → Wash the mask every day in warm water with mild soap (removes residue and allergens)
- → Use fabric or gel liners between the mask and your skin
- → Try a mask made of another material: a foam cushion (ResMed AirTouch range) or a fabric mask
- → See a dermatologist to confirm the allergy (patch test)
- → Report the reaction to your provider so they can offer an alternative
Remember: A true silicone allergy is rare, but it does happen. If daily washing does not help, tell your provider: there are alternatives.
Nasal congestion and a blocked nose
CommonWhy it happens
CPAP sends a continuous stream of air through your nose all night. Without enough humidification, it dries out the lining of the nose, which reacts by swelling and producing more mucus: hence the blocked nose in the morning.
Solutions
- → Turn on or turn up the heated humidifier
- → Use a saline nasal spray (Humer, Physiomer) before bed
- → Make sure the tubing is not exposed to cold air (condensation)
- → Use heated tubing (ResMed ClimateLineAir, for example) to stop water collecting in the tube
- → If you have allergic rhinitis, treat the allergy itself
Remember: Chronic nasal congestion on CPAP is usually solved by a properly adjusted humidifier. It is one of the most common reasons CPAP is hard to tolerate.
Nosebleeds (epistaxis)
UncommonWhy it happens
The lining of the nose dried out by the airflow, especially in winter or in a dry room (central heating). The small, fragile vessels of the septum can bleed.
Solutions
- → A heated humidifier: the main solution
- → Apply a moisturizing nasal gel (Nozoil, Sterimar gel) inside the nostrils before bed
- → Drink enough water during the day
- → Humidify the bedroom (room humidifier)
- → If the bleeding persists or is heavy: see an ENT specialist
Remember: Nosebleeds almost always stop once the humidifier is set right. Do not just put up with them.
Air leaks (sore eyes, conjunctivitis)
CommonWhy it happens
Leaks around the nose or cheeks blow air into your eyes during the night. In the morning: red, irritated, watering eyes, sometimes repeated conjunctivitis.
Solutions
- → Readjust the mask: reposition the straps rather than tightening them
- → Change the cushion size (too small means leaks at the sides)
- → Replace a worn cushion (every 3 to 6 months, depending on the manufacturer)
- → Try a mask of a different shape or type (nasal pillows or nasal)
- → Your CPAP records how much it leaks: go through the data with your provider
Remember: Your CPAP measures and records leaks. A high leak rate makes treatment less effective, and your provider can check it remotely. Note: some leaking is normal and deliberate (the mask's intentional leak). Never block it.
Understanding intentional leak (the exhalation vent) → FRDifficulty breathing out
Common at the startWhy it happens
CPAP blows air continuously, including while you breathe out. Some patients feel resistance when they exhale, especially at high pressure or at the start of treatment. It can feel like suffocating, or fighting the machine.
Solutions
- → Turn on EPR (ResMed) or C-Flex (Philips): the pressure drops when you breathe out
- → Switch to auto-CPAP: the pressure adapts and is often lower on average
- → Use the ramp: the pressure starts low and rises gradually while you fall asleep
- → Do a few deep nasal breathing exercises before going to sleep
- → See your doctor if it still feels this way after 2 to 3 weeks
Remember: Resistance when breathing out is normal at first. It usually goes away after 1 to 3 weeks. If it does not, the EPR or C-Flex setting makes all the difference.
Claustrophobia and mask anxiety
Common at the startWhy it happens
Having a mask on your face triggers a feeling of being shut in or smothered, especially in anxious people. It can cause panicked awakenings, or a refusal to wear the mask.
Solutions
- → Start by wearing the mask during the day, without the machine, to get used to it
- → Choose the least bulky mask possible (nasal pillows)
- → Wear the mask with the machine running for a few minutes before going to sleep
- → Relax: breathe slowly and deeply as you put the mask on
- → If the anxiety is severe: talk to your doctor (psychological support can help)
Remember: A nasal pillows mask (two small tips that sit in the nostrils) is often the best tolerated by people with claustrophobia: it leaves your field of vision clear and covers as little of your face as possible.
Acne and contact spots
UncommonWhy it happens
Long contact between the mask and your skin, warmth and moisture encourage bacteria. A mask that is not cleaned properly collects oil and bacteria, which cause spots on the nose, cheeks or chin.
Solutions
- → Wash the mask every morning in warm water with mild, unscented soap
- → Clean your face before putting the mask on (night cream, make-up)
- → Avoid greasy or oily creams on your face before bed
- → Replace the mask cushion every 3 months
- → Use CPAP mask wipes on days when washing is not possible
Remember: A clean mask means fewer skin problems. Cleaning the cushion every day is not optional.
Machine noise
Varies by modelWhy it happens
Modern CPAP machines are quiet (25 to 30 dB, quieter than a refrigerator). But air leaking from the mask can whistle or hiss and disturb your partner.
Solutions
- → Reduce mask leaks (see the section on leaks)
- → Route the tubing behind your head, or use a swivel tube
- → Put the machine on a sound-absorbing surface (a thick towel)
- → Offer your partner earplugs
- → If the machine itself is noisy: have your provider check it (a clogged filter?)
Remember: Most noise comes from the mask, not the machine. Fixing the leaks usually fixes the noise.
Central apneas on treatment (complex sleep apnea)
Uncommon, often temporaryWhy it happens
In some patients, CPAP removes the obstructive apneas but central apneas appear (for a moment, the brain stops sending the signal to breathe). This is called treatment-emergent central sleep apnea, or complex sleep apnea. It shows up in your CPAP data.
Solutions
- → Monitoring of your CPAP data: residual central apneas appear in the reports
- → Often temporary: they go away within a few weeks in most patients
- → If they persist: an appointment at the sleep center to reassess
- → Possible treatment with adaptive servo-ventilation (ASV)
- → Do not change the settings yourself without medical advice
Remember: This is often picked up during remote monitoring. Do not stop CPAP without medical advice.
A side effect that will not go away?
Your CPAP provider is the first person to call. Under the NIHDI convention, follow-up and adjustments are included: call them, it is their job. If the problem is medical (pressure to reassess, residual apneas), your sleep center takes over.
Sources
- Patil SP, et al. Treatment of Adult OSA With Positive Airway Pressure: AASM Clinical Practice Guideline. J Clin Sleep Med. 2019;15(2):335-343.
- Gottlieb DJ, Punjabi NM. Diagnosis and Management of Obstructive Sleep Apnea. JAMA. 2020;323(14):1389-1400.
- Jacobsen AR, et al. Determinants for Adherence to CPAP Therapy in OSA. PLoS One. 2017;12(12):e0189614.
- Patel SR, et al. Age and Sex Disparities in Adherence to CPAP. Chest. 2021;159(1):382-389.
