Continuous Positive Airway Pressure (CPAP) therapy is the most effective treatment for sleep apnea, but it can occasionally lead to uncomfortable side effects—one of the most common being dry mouth. If you’re consistently waking up with a dry mouth or sore throat after using your CPAP machine, you’re not alone.

Fortunately, this issue is typically easy to resolve with the right adjustments. In this blog we’ll cover the most common causes of CPAP-related dry mouth and offer practical solutions to alleviate the problem so you can get a restful sleep each night.

Dry mouth during CPAP use can result from a variety of factors. In some cases, the cause may be unrelated to your CPAP device, mask, or CPAP supplies. In others, specific settings or equipment choices may contribute directly to the issue.

• High pressure settings may dry out the airways, especially if not balanced with proper humidification from either the CPAP machine, sleep environment, or both.

• Excess pressure can cause users to open their mouths during sleep, especially if they’re not using a full face mask.

Overall inaccurate CPAP settings, whether too high or too low, can also be a cause for drying out your mouth during treatment.

• Using a CPAP machine without a humidifier can dry the airways and mouth.

• A low humidity setting or dry ambient air (common in winter or desert climates) can worsen the effect.

• Heated humidifiers not working properly or water chambers not being refilled adequately may reduce effectiveness.

Your humidification settings may need to be readjusted as most CPAP machines today have customizable settings that can drastically affect the amount of humidification you receive with your treatment.

• Sleeping in a room with low ambient humidity or excessive air circulation (e.g., fans, air conditioning) can contribute to dryness.

• Allergens or dust in the room may cause nasal congestion, prompting mouth breathing during sleep.

• Congestion due to allergies, colds, sinus infections, or a deviated septum can force mouth breathing even when using a nasal mask.

• CPAP users with frequent nasal congestion may struggle to maintain a nasal breathing pattern, leading to dry mouth.

• Mask vent position or design: Some masks vent air in a direction that flows back toward the mouth or face, increasing evaporation around the lips and oral cavity. 

• Improper CPAP hose positioning: If the hose tugs or pulls while you move during sleep, it may break the seal of your mask subtly, causing small leaks near the mouth.

• Some machines may not be optimally set up, such as having ramp time disabled, causing users to get full pressure immediately, which can increase air swallowing, leading to dryness.

• In auto-adjusting CPAP machines (APAP), rapid pressure increases during the night may promote air leakage or mouth opening. It’s important to troubleshoot your machine settings as soon as you notice side effects like dry mouth with your healthcare provider to ensure there isn’t a deeper issue with your CPAP device.

If CPAP-related dry mouth is disrupting your therapy, the following suggestions may help improve comfort and serve as solutions to alleviate this side effect...

Users who breathe through their mouth during sleep may benefit from switching to a full face mask. This type of mask covers both the nose and mouth, ensuring consistent pressure delivery regardless of breathing route. It can reduce both dry mouth symptoms and therapy air loss.

If you already use a full face CPAP mask, consider switching mask types, brands, or adding comfort products to ensure a proper seal.

CPAP humidifiers add moisture to the airflow, which can prevent dryness in the nose, throat, and mouth. Heated humidifiers are especially effective in reducing irritation and congestion that may contribute to mouth breathing.

Research indicates that users who incorporate a humidifier are significantly more likely to remain consistent with their CPAP therapy. A heated humidifier can help alleviate dry mouth by moisturizing the airflow, reducing nasal dryness and throat irritation.

When purchasing a humidifier chamber for your CPAP machine, ensure it is compatible with the machine you use; humidifier chambers may not be interchangeable between machines.

A chin strap can support the lower jaw during sleep, helping to keep the mouth closed and promoting nasal breathing. This simple accessory is often effective for habitual mouth breathers and can enhance both comfort and treatment compliance.

A chin strap helps keep the mouth closed during sleep and promotes nasal breathing, reducing the chances of waking up with a dry mouth.

Frequent cleaning of CPAP equipment helps reduce dry mouth by removing bacteria, mold, and debris that can irritate airways and lead to mouth breathing. It ensures the humidifier works efficiently to deliver proper moisture, helps maintain a secure mask seal to prevent air leaks around the mouth, and keeps the tubing clear for consistent airflow and humidity

Reusable or disposable mask liners reduce skin irritation and may improve seal, decreasing leaks that dry out the mouth.

Specialty pillows accommodate mask frames and hoses, helping reduce positional leaks or mouth opening caused by poor neck posture.

This accessory prevents the hose from dragging the mask out of position and causing leaks that dry out your mouth.

Train your tongue to rest against the roof of your mouth (myofunctional therapy techniques), which supports mouth closure and nasal breathing during sleep.

If your room has especially dry air, a standalone room humidifier can complement your CPAP machine’s built-in humidifier.

Water-based oral gels can provide overnight moisture without interfering with CPAP masks.

Some users find silicone irritating and switch to memory foam or gel cushions that offer a better seal and increased comfort.

Enabling or lengthening the ramp period may help you fall asleep more comfortably, reduce early mouth breathing, and minimize early-night dryness.

Keeping the nasal passages clear and moist can reduce reliance on mouth breathing and increase humidification efficiency.

Some users find that certain machines deliver air more comfortably, or that humidification is more effective with one manufacturer over another.