CPAP does not damage healthy lungs. For most people with sleep apnea, it protects the lungs and heart by keeping oxygen levels steady through the night.

That said, CPAP is a medical device, and a few lung-related concerns deserve a clear answer. These include infections from dirty equipment, air going into the stomach, the Philips foam recall, and how CPAP affects people who already have asthma or COPD.

This article walks through each concern and what recent studies say about it.

How CPAP Works

CPAP stands for continuous positive airway pressure. A small machine pushes room air through a hose and mask. That gentle pressure holds your throat open so it does not collapse while you sleep.

The pressure works mainly in your throat, not deep in your lungs. Typical CPAP pressure is low. In a large French study of more than 1,400 long-term users, the average pressure was about 8 cm of water. That is far lower than the pressures used on breathing machines in intensive care units.

Does CPAP Harm Healthy Lungs?

No study in the last five years shows that CPAP, used as prescribed for sleep apnea, damages normal lung tissue.

The bigger picture points the other way. A 2025 meta-analysis in The Lancet Respiratory Medicine pooled 30 studies, including 10 randomized controlled trials, with more than 1.1 million people. People using positive airway pressure had about a 37% lower risk of death from any cause and a 55% lower risk of death from heart disease compared with untreated people. The benefit grew with more nightly use.

A note on the evidence: most of those participants came from observational studies, and the analysis was funded by a CPAP manufacturer. The results are encouraging but should be read with that in mind.

Bottom line: untreated sleep apnea is the bigger threat to your heart and lungs, not the CPAP machine.

Air in the Stomach, Not the Lungs

Some people feel bloated, burp often, or pass more gas after using CPAP. This is called aerophagia, which means swallowing air. The air goes into the stomach, not the lungs.

Recent studies show how common it is:

• A 2025 study of 1,461 CPAP users found that 8.3% reported aerophagia.
• A 2024 study of 753 patients found a rate of 7.2%.

Aerophagia was more likely in people with higher pressure settings, younger adults, women, people with lower body weight, and people with acid reflux. It is uncomfortable but not dangerous to the lungs.

What helps:

• Ask your sleep doctor to review your pressure settings.
• Ask about switching to auto-adjusting CPAP or bilevel PAP, which can lower the pressure you breathe out against. A 2023 study found switching to bilevel reduced aerophagia symptoms.
• Treat acid reflux if you have it.
• Sleep with your head slightly raised.

Infections and Dirty Equipment

This is the most practical lung concern for CPAP users. Warm, moist air in the mask, hose, and water chamber can grow bacteria and mold if the equipment is not cleaned.

A 2025 case report described a man with COPD who developed Pseudomonas pneumonia, a serious lung infection. He admitted to poor cleaning and had noticed green growth on his mask.

A 2025 study of more than 650,000 matched patients found that people prescribed CPAP had slightly higher odds of a pneumonia diagnosis in the following year (about 6% higher) and higher odds of being hospitalized for pneumonia (about 24% higher). This study had real limits. It used health records only, could not confirm whether people actually used or cleaned their machines, and could not prove CPAP caused the infections. People who get CPAP also tend to be older and sicker. It was funded by a vaccine manufacturer.

On the other side, a 2026 review found that untreated sleep apnea itself raises pneumonia risk. Low oxygen, poor sleep, and small amounts of saliva slipping into the airway all weaken the lungs’ defenses. CPAP may reduce some of this risk, as long as the equipment stays clean.

Weaker evidence note: there are no randomized trials on CPAP and pneumonia. Current guidance relies on observational data and case reports.

How to keep your equipment clean:

• Rinse the mask cushion daily and let it air dry.
• Empty the humidifier chamber every morning. Do not top it off with old water.
• Use distilled water in the humidifier.
• Wash the mask, tubing, and water chamber weekly with warm water and mild soap.
• Replace the filter, mask cushion, and tubing on the schedule your supplier gives you.
• Throw out any part with visible mold, slime, or discoloration.
• Clean more often when you have a cold.

The Philips Recall and Cancer Concerns

In June 2021, Philips Respironics recalled millions of CPAP and BiPAP machines. A sound-reducing foam inside the machines could break down. Users could breathe in tiny foam particles or chemicals released from the foam. Many people worried about lung damage and cancer.

The best available data are reassuring:

• A 2024 Canadian study followed 231,692 CPAP users for a median of 6.3 years. About 25% used recalled Philips devices. After accounting for other health factors, there was no meaningful difference in cancer risk between recalled devices and other brands.
• A 2022 French study of 4,447 patients who used CPAP consistently found no increase in cancer risk with Philips devices over about 7 years.
• A 2022 Swedish study first found slightly more cancer in regions that used the foam devices. That difference disappeared once researchers removed one region known for higher smoking rates.

Weaker evidence note: these are observational studies. None tracked smoking perfectly, and cancer can take many years to develop. Experts describe the current data as reassuring but not final.

What to do:

• If you still have a recalled device, contact your equipment supplier about a replacement.
• Do not stop CPAP on your own without talking to your doctor. Untreated sleep apnea carries real risks.
• Avoid ozone-based CPAP cleaners. Philips and the FDA reported that ozone can speed up foam breakdown, and ozone cleaners are not an approved cleaning method.

If You Have COPD

COPD is a long-term lung disease that includes emphysema and chronic bronchitis. When COPD and sleep apnea occur together, it is called overlap syndrome. People with both conditions have lower oxygen at night and worse outcomes than people with either one alone.

A 2023 systematic review found that CPAP in people with overlap syndrome was linked to fewer COPD flare-ups, fewer hospital stays, and lower death rates. A 2026 review reached a similar conclusion for people who have sleep apnea symptoms.

Some people with COPD need more than CPAP:

• If you have high carbon dioxide levels during the day, your doctor may recommend bilevel PAP or noninvasive ventilation instead.
• If your oxygen is low during the day, you may need supplemental oxygen added to your PAP.

Weaker evidence note: large randomized trials in overlap syndrome are still lacking. Most of the data come from observational studies.

If You Have Asthma

Asthma and sleep apnea often occur together. Untreated sleep apnea can make asthma harder to control and can increase airway inflammation.

A 2025 review found that CPAP had a positive effect on asthma control, symptoms, and inflammation in people with both conditions. CPAP does not irritate or tighten the airways in people with asthma.

Weaker evidence note: high-quality randomized trials are limited. A randomized trial testing CPAP in severe, uncontrolled asthma (the ASTHMA-SLEEP trial) is now underway and should give clearer answers.

CPAP and Lung Blood Pressure

Sleep apnea can raise blood pressure in the arteries of the lungs. This is called pulmonary hypertension. Over time, it strains the right side of the heart.

Two recent meta-analyses found CPAP lowers this pressure:

• A 2025 analysis of people who already had pulmonary hypertension found an average drop of about 8.6 mmHg after PAP therapy, though results varied widely between studies.
• A 2026 analysis that included two randomized trials found an average drop of about 2.3 mmHg in people with sleep apnea or obesity-related breathing problems.

This is a direct lung benefit of treating sleep apnea.

Rare Situations to Discuss With Your Doctor

A collapsed lung caused by CPAP is extremely rare at the pressures used for sleep apnea. Still, tell your sleep doctor before starting CPAP if you have:

• A past collapsed lung (pneumothorax)
• Large air pockets in the lungs, called bullae, often seen in severe emphysema
• Recent chest, lung, or sinus surgery
• A recent head or face injury
• Ongoing nosebleeds or a leak of fluid from the nose

Your doctor may adjust your pressure, choose a different machine, or recommend another treatment.

Summary Table

Concern	What the research shows	Strength of evidence
Damage to healthy lungs	No evidence of harm. Treatment linked to lower death rates	Meta-analysis including RCTs, mostly observational
Air in the stomach	Affects about 7% to 8% of users. Goes to the stomach, not lungs	Observational studies
Pneumonia and infection	Small possible increase, likely tied to dirty equipment and sicker patients	Observational studies and case reports
Philips foam recall	No meaningful increase in cancer risk after adjusting for other factors	Large observational studies
COPD	Fewer flare-ups, hospital stays, and deaths	Systematic review of observational studies
Asthma	Better control and less inflammation	Reviews, limited RCT data
Lung blood pressure	Lower pressure in lung arteries	Meta-analyses including some RCTs

Practical Takeaways

• Use your CPAP every night, for the whole night if you can. The benefits grow with more use.
• Clean your mask and humidifier daily and the whole system weekly.
• Use distilled water and replace parts on schedule.
• Skip ozone cleaners.
• Report bloating, burping, chest pain, or a new cough to your sleep doctor.
• If you have COPD, asthma, or a past collapsed lung, make sure your sleep doctor knows.
• If you have a recalled device, ask for a replacement but keep treating your sleep apnea.

When to Call Your Doctor

Call your doctor if you notice:

• Fever, cough with colored mucus, or shortness of breath
• Sudden chest pain or sudden trouble breathing (seek emergency care)
• Mold or discoloration on your equipment that will not clean off
• Bloating or stomach pain that keeps you from using CPAP
• Worsening asthma or COPD symptoms after starting CPAP

Disclaimer

This article is for educational purposes only and does not replace medical advice from your own doctor. Every person’s health situation is different. Talk with your sleep physician or healthcare provider before starting, stopping, or changing any treatment, including CPAP therapy.

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References

1. Benjafield, A. V., Pépin, J. L., Cistulli, P. A., Wimms, A., Lavergne, F., Sert Kuniyoshi, F. H., Munson, S. H., Schuler, B., Reddy Badikol, S., Wolfe, K. C., Willes, L., Kelly, C., Kendzerska, T., Johnson, D. A., Heinzer, R., Lee, C. H., & Malhotra, A. (2025). Positive airway pressure therapy and all-cause and cardiovascular mortality in people with obstructive sleep apnoea: A systematic review and meta-analysis of randomised controlled trials and confounder-adjusted, non-randomised controlled studies. The Lancet Respiratory Medicine, 13(5), 403–413.
2. Fabozzi, A., Bouloukaki, I., Bonini, M., Schiza, S. E., & Palange, P. (2025). Asthma-OSA overlap syndrome: A distinct endophenotype? Respiratory Medicine, 248, 108344.
3. Fukutome, T. (2024). Prevalence of continuous positive airway pressure-related aerophagia in obstructive sleep apnea: An observational study of 753 cases undergoing CPAP/BiPAP treatment in a sleep clinic, part one of a two-part series. Sleep and Breathing, 28, 2481–2489.
4. Hospital Clinic of Barcelona. (2023). Effect of CPAP treatment in patients with severe uncontrolled asthma: The ASTHMA-SLEEP trial (ClinicalTrials.gov Identifier NCT06314477). U.S. National Library of Medicine.
5. Justeau, G., Gervès-Pinquié, C., Jouvenot, M., Pigeanne, T., Launois, S., Leclair-Visonneau, L., Masson, P., Bizieux-Thaminy, A., Bailly, S., Meslier, N., Sabil, A., Racineux, J.-L., Trzepizur, W., & Gagnadoux, F. (2022). Cancer risk in adherent users of polyurethane foam-containing CPAP devices for sleep apnoea. European Respiratory Journal, 60(1), 2200551.
6. Kaddah, S., & Esquinas, A. M. (2026). The interplay between obstructive sleep apnea and respiratory infections: A review article. Thoracic Research and Practice, 27(2), 120–128.
7. Kendzerska, T., Pendharkar, S. R., Talarico, R., Blades, K., Mackenzie, C., Gershon, A. S., Ayas, N., Kaminska, M., Fenton, M., McBrien, K. A., Hawken, S., Ratycz, D., Lishchenko, V., Owens, R. L., & Povitz, M. (2024). Association between a recalled positive airway pressure device and incident cancer: A population-based study. European Respiratory Journal, 64(5), 2400560.
8. Li, J., Zhao, J., Pang, P.-P., Zhai, W.-J., Wang, Y.-K., Zhang, X.-Y., & Wei, Y.-Q. (2026). Continuous positive airway pressure effects on pulmonary hemodynamics and left ventricular function in obstructive sleep apnea and obesity hypoventilation syndrome: A systematic review and meta-analysis. Canadian Respiratory Journal, 2026(1), e3020878.
9. Mando, N., Antonious, D., Gillen, N., Joseph, M., & Thomson, E. (2025). Pseudomonas unmasked: Poor continuous positive airway pressure (CPAP) hygiene leads to a case of Pseudomonas pneumonia. Cureus, 17(1), e77697.
10. Marin-Oto, M., & Marin, J. M. (2024). Obstructive sleep apnea effects on chronic airway disease exacerbations: Missed opportunities for improving outcomes in chronic obstructive pulmonary disease and asthma. Sleep Medicine Clinics, 19(2), 275–282.
11. Palm, A., Grote, L., Ekström, M., & Ljunggren, M. (2022). Health risks related to polyurethane foam degradation in CPAP devices used for sleep apnoea treatment. European Respiratory Journal, 59(5), 2200237.
12. Palot, A., Nguyên, X. L., Launois, S., Prigent, A., Graml, A., Aversenq, E., Koltes, C., Recart, D., & Lavergne, F. (2023). Effect of switching from continuous to bilevel positive airway pressure on sleep quality in patients with obstructive sleep apnea: The prospective POP IN VAuto study. Journal of Thoracic Disease, 15(2), 918–927.
13. Philips Respironics. (2022, May 24). Philips Respironics provides update on filed MDRs in connection with the voluntary recall notification/field safety notice for specific CPAP, BiPAP and mechanical ventilator devices [Press release].
14. Sarvananda, S., Earnshaw, S., Hughes, I., Sivakumaran, P., & Sriram, K. B. (2025). Effect of positive airway pressure treatment on pulmonary artery pressure in obstructive sleep apnoea and/or obesity hypoventilation syndrome with pulmonary hypertension: A systematic review and meta-analysis. Internal Medicine Journal, 55(8), 1281–1292.
15. Shah, A., & Mandal, S. (2026). Examining the need for positive airway pressure in patients with COPD-OSA overlap. Expert Review of Medical Devices, 23(7), 839–844.
16. Srivali, N., Thongprayoon, C., Tangpanithandee, S., Cheungpasitporn, W., & Won, C. (2023). The use of continuous positive airway pressure in COPD-OSA overlap syndrome: A systematic review. Sleep Medicine, 108, 55–60.
17. Sunwoo, B. Y., Raphelson, J. R., & Malhotra, A. (2024). Chronic obstructive pulmonary disease and obstructive sleep apnea overlap: Who to treat and how? Expert Review of Respiratory Medicine, 18(7), 527–537.
18. Tort, M. J., Emir, B., Nguyen, J. L., Malhotra, D., Kim, C. H., & Snow, V. T. (2025). Association of CPAP prescription and pneumonia among patients with obstructive sleep apnea in the United States: A retrospective database analysis. Advances in Therapy, 42(11), 5669–5682.
19. Vidal, C., Mallet, J.-P., Skinner, S., Gilson, R., Gaubert, O., Prigent, A., Gagnadoux, F., Borel, J.-C., Bourdin, A., Molinari, N., & Jaffuel, D. (2025). Positive airway pressure-related aerophagia in obstructive sleep apnea: Results from the InterfaceVent real-life study. Journal of Clinical Medicine, 14(18), 6424.