How to Prevent Dry Mouth During CPAP Therapy

Common Causes and Treatments

If you struggle with mouth breathing and dry mouth while using continuous positive airway pressure (CPAP) therapy for sleep apnea, there are several things you can do that will help.

Different treatments can help improve nasal congestion that can lead to mouth breathing. Making adjustments to the CPAP device itself can also help.

This article will discuss why mouth breathing is common in people who use CPAP and what can be done to fix this problem.

Mannequin head with CPAP Chinstrap used to keep your mouth closed
Brandon Peters, M.D.

Mouth Breathing on CPAP

Mouth breathing is a common problem among CPAP users. The CPAP works by delivering a constant flow of air that is meant to keep your upper airway open so you can breathe easy.

However, if your mouth falls open while the air is being delivered through your nose via a mask, it will escape, causing your mouth or throat to dry out. Over time, this may also lead to problems with your gums or teeth. Most importantly, it may reduce or eliminate the effectiveness of your treatment.

Mouth breathing is most often the result of a nasal blockage, such as caused by a deviated septum, allergy, or nasal infection. Conditions like these can cause tissues known as turbinates to swell and obstruct the normal airflow.

If you are a mouth breather during the day, there is a high chance that you are also a mouth breather at night.


You can prevent dry mouth with a CPAP by using treatments to clear nasal blockage and discourage mouth breathing.

It's important to make sure you can breathe through your nose without a sense of obstruction or restriction. If you have allergies, you may need to speak to your healthcare provider about treating them with oral medications or nasal steroids.

You may also find it helpful to rinse your nose with saline from a neti pot, which delivers warm water into your nose and sinuses. Drinking a little water or using Biotene rinse at night may also help.

If you have a deviated septum, this may need to be corrected with surgery. Turbinates may also be reduced with a surgical procedure that may open the nose. These surgeries are typically done by an ear, nose, and throat (ENT) specialist.

If the dryness is related to your mouth falling open, a chinstrap may help. A chinstrap is a simple headpiece, often fitted with Velcro, that is secured around your chin and the top of your head to keep your jaw shut. While useful, a chinstrap is not always comfortable and may cause snoring or a lip-buzzing sound as the air tries to escape.

Other interventions and alternative therapies for obstructive sleep apnea include weight loss, oral appliances, and positional therapy.

While some people have been known to tape their lips during CPAP to prevent mouth breathing, the practice is strongly discouraged due to the risk of vomiting, aspiration, and asphyxiation.

Overcoming Equipment Issues

The next likely culprit for dry mouth may be your CPAP mask or machine. If the mask is not fitting properly, it may leak or cause moisture to be lost, defeating the entire purpose of the device. This is not uncommon with CPAP devices that fit over the nose which have the tendency to shift.

If your CPAP mask is the problem, one solution is to find a full-face mask that covers your nose and mouth or a total-face model that covers the eyes as well. The mask would need to be fitted to prevent leakage and ensure the lower jaw is not shifted.

Your CPAP machine should ideally be fitted with an adjustable heated humidifier to keep the nose, mouth, and throat moist. The air pressure settings may also need to be adjusted as overly high pressure can cause the mouth to fall open.

If you have old equipment, you should have it checked. In some cases, you may not have any other option but to replace the unit if it is unable to meet your needs any longer.


CPAP therapy is a common and effective treatment for people with obstructive sleep apnea. However, mouth breathing is common among CPAP users and can reduce the effectiveness of the therapy. Fortunately, there are many ways to avoid mouth breathing.

A Word From Verywell

If your problems persist, you may need to seek out other interventions. It may be necessary to have a repeat sleep study to ensure that you have a proper amount of pressure delivered.

In some cases, it may be helpful to switch to bilevel therapy (BiPAP) in which the device delivers two distinct pressures, one for inhalation and the second for exhalation.

Despite any difficulties you may encounter, it is vital not to give up. Compliance with CPAP therapy may be tough, particularly in the early days, but the avoidance of serious sleep apnea complications makes it well worth it.

If you're struggling with CPAP therapy, tell your sleep medicine specialist and keep at it until a solution can be found.

4 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. The American Sleep Apnea Association. CPAP machines.

  2. Madison S, Brown EA, Franklin R, Wickersham EA, Mccarthy LH. Clinical Question: Nasal saline or intranasal corticosteroids to treat allergic rhinitis in children. J Okla State Med Assoc. 2016;109(4-5):152-3.

  3. Van egmond MM, Rovers MM, Hendriks CT, Van heerbeek N. Effectiveness of septoplasty versus non-surgical management for nasal obstruction due to a deviated nasal septum in adults: study protocol for a randomized controlled trial. Trials. 2015;16:500. doi:10.1186/s13063-015-1031-4

  4. Johnson KG, Johnson DC. Treatment of sleep-disordered breathing with positive airway pressure devices: technology update. Med Devices (Auckl). 2015;8:425-37. doi:10.2147/MDER.S70062

By Brandon Peters, MD
Brandon Peters, MD, is a board-certified neurologist and sleep medicine specialist.