Common Side Effects of CPAP Therapy

Apnea Medical Test
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If you have been prescribed continuous positive airway pressure (CPAP) to treat obstructive sleep apnea, you may wonder what side effects are associated with its use. Fortunately, CPAP therapy is relatively safe. The most common complaints relate to discomfort from the mask interface or air pressure. Discover what can go wrong if you use CPAP therapy to resolve snoring and sleep apnea.

Skin Marks or Rashes from CPAP

Your CPAP mask may leave marks on your skin if it doesn't fit properly. It is possible this may lead to sores or even ulcers, especially along the bridge of your nose. People with sensitive skin may also develop a rash or skin irritation, especially with masks that contain latex. Mask liners, barrier creams, loosening the mask, or a better-fitted mask may relieve these symptoms.

Air Leaking from CPAP Masks

By far, a leak is the most common complaint associated with CPAP use. If the mask does not fit perfectly, air may escape around the edges. It can get worse if you change position during the night. Larger mask, such as those that cover the nose and mouth, are more prone to leaks. These leaks may be noisy and disturb your bed partner. Leaks may also compromise your therapy by reducing the pressure delivered. The leak may be reduced by using a nasal mask or nasal pillows.


If you are struggling with the fit of your CPAP mask, lower pressure settings can sometimes be helpful. If there is too much air pressure, the excessive air escapes around the edges of the mask or out of the mouth. Discuss this with your doctor before changing the settings.

Dryness in the Nose or Mouth from CPAP

Dryness of your nose or mouth often accompanies leakage.

This may lead to nosebleeds or even damage to your gums and teeth. Using a heated humidifier and heated tubing can help make your CPAP more comfortable. If your mouth falls open, air can escape and that can lead to a parched mouth or tongue. Using a chinstrap or a full-face mask that covers both the nose and mouth may correct this. If your nose is dry, over-the-counter nasal saline spray can help.

Discomfort Breathing Out

When you first start using CPAP therapy, there is a period of adjustment that occurs. It may not feel natural to breathe out against the pressure. Though it is easy to breathe in, you may find it difficult to breathe out. This may improve over time, but it may also provoke insomnia. In some cases, ramping from a lower initial pressure or a feature to allow easier exhalation can be helpful. It may be necessary to reduce the pressures overall. In rare cases, bi-level therapy—in which one pressure is used to breathe in, and a lower pressure is used to breathe out—may be needed.

Air Swallowing or Aerophagia from CPAP

Many people experience air swallowing, called aerophagia (literally "air eating"). If you wake and your stomach is filled with air, this may be due to aerophagia.

 Air swallowing can be a sign of CPAP pressures that are too high. Rather than supporting the upper airway, the excessive air can enter the stomach via the esophagus. As a result, burping, farting, and bloating can become problems. Reduced pressures may help to alleviate this. Other treatments for aerophagia like the use of medication for heartburn or GERD, sleeping wedge pillows, and bi-level therapy may also be helpful.

Developing Central Sleep Apnea

Some people will start to experience central sleep apnea, in which breath holding occurs as a response to CPAP therapy. If central apneas did not account for the majority of your breathing disturbances before starting CPAP, but now they contribute to more than five events per hour, it may represent complex sleep apnea.

This sometimes resolves in time. It may require a change to ASV therapy. In other cases, it may be alleviated by simply lowering the CPAP pressure.

Face Growth Problems in Children Who Use CPAP

Children who use CPAP should be monitored so that they do not develop growth problems of their mid-face related to the pressure of the mask across the nose. Newer mask styles, including nasal pillows, may reduce this risk.

Changes That Affect The CPAP Pressure You Require

Sometimes it is necessary to lower the pressures of the CPAP machine when your risk factors for sleep apnea have changed. Excessive weight is one of the biggest contributors to sleep apnea risk. If you can lose at least 10 percent of your body weight through diet and exercise, you may require lower CPAP pressure. If you start to have problems with air swallowing, mask leak, or difficulty breathing out against the pressure, this is likely to be helpful.

If you have environmental allergies, optimized treatment with medications or nasal sprays could reduce you pressure requirements by improving airflow through the nasal passage. Also, surgical changes—including tonsillectomy, nasal septoplasty, and soft palate or tongue surgery—may alter your CPAP therapy requirements.

Substance use can impact the risk of sleep apnea. If you smoke, snoring and sleep apnea may worsen. Alcohol use near bedtime can cause muscle relaxation and contribute to sleep apnea. Medications, including muscle relaxants and benzodiazepines, may worsen sleep apnea. If you discontinue use of any of these substances, your sleep apnea risk may decline and your pressure needs may also be reduced.

A Word From Verywell

If you experience any of these side effects or suspect you may need to reduce your CPAP pressure, speak with your sleep specialist or equipment provider about the solutions that are available to you. After review of your CPAP data, a determination can be made on how best to change your pressure settings or make other changes. As this is a prescribed therapy with multiple variables to consider, don't make these changes on your own. Fortunately, changes can often be made to improve the experience with CPAP therapy and to reduce the side effects.

View Article Sources
  • Kryger MH, Roth T, Dement WC. Principles and Practice of Sleep Medicine. Philadelphia, PA: Elsevier; 2017.