Fortunately, CPAP therapy is relatively safe. The most common complaints relate to discomfort from the mask interface or air pressure. If improperly fitted, the mask may leave marks on the skin. If this pressure persists it may begin to damage the skin of the face, leading to sores or even ulcers, especially along the bridge of the nose. People with sensitive skin may also develop a rash or skin irritation, especially to masks that contain latex.
By far, leak is the most common complaint associated with CPAP use. If the mask does not fit perfectly, air may escape around the edges. Position changes during the night may exacerbate this. This is worse with larger masks, such as those that cover the nose and mouth, as there is more surface area and potential for leak. These leaks may be noisy and disturb bed partners. Leaks may also compromise the therapy by reducing the pressure delivered.
Often accompanying leak is dryness, affecting either the nose or mouth. This can be greatly improved with the use of a heated humidifier and heated tubing. When the humidity temperature is set high enough, CPAP can be quite comfortable. However, if the mouth falls open, air may escape and lead to a parched mouth or tongue. The use of a full-face mask that encompasses both the nose and mouth or a chinstrap may correct this. If the nose is dry, over-the-counter nasal saline spray can help.
Finally, many people experience air swallowing, called aerophagia (literally "air eating"). Aerophagia occurs when the air that is meant to go into the lungs via the trachea instead goes into the nearby esophagus that leads to the stomach. This may lead to gas: burps or belches, farting, or a bloated stomach. If it is relatively minor, it is generally tolerated as the air is passed back out easily. If the discomfort is significant, it may be necessary to decrease the pressure setting, raise the head of the bed, or take a medication for heartburn.
It should be noted that 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.
If you experience any of these side effects, speak with your sleep specialist or equipment provider about the solutions that are available to you.
Kryger, MH et al. "Principles and Practice of Sleep Medicine." ExpertConsult, 5th edition, 2011.