Do You Have to Use the Humidifier with CPAP?

Inconvenience May Outweigh Benefits of Reducing Dry Nose or Mouth

The removable water chamber should be filled with distilled water when used with the ResMed S9 CPAP Machine.. Brandon Peters, M.D.

Most newer continuous positive airway pressure (CPAP) or bilevel machines now come with a heated humidifier that is either fully integrated into the device or easily attached. You may wonder if you have to use the humidifier with your CPAP. Learn about the benefits of using a humidifier and whether it is something that you can simply do without.

What Is the Purpose of the CPAP Humidifier?

Many people find benefit in using their CPAP’s humidifier.

It is typically designed to be a detachable portion of the machine. It contains a chamber or tank that can be filled with distilled water. Beneath this chamber, a hot plate heats the water and turns a portion of it into humidity. The pressurized room air is then passed by it and this moisture is delivered to the airway, from the nose into the throat and to the lungs. Settings can be adjusted, with automatic settings as well as manual controls, including the amount of water boiled off and the temperature of the heated tubing.

This humidified air can reduce irritation along the airway and may help to relieve dryness from therapy. The airflow can be drying, especially if the mouth comes open at night. An open mouth, especially if nasal obstruction is present due to allergies or a deviated septum, will lead to air escape that can quickly cause a dry mouth and sore throat. In some cases, a full-face mask or chinstrap may be needed to prevent this from occurring.

In extreme cases, the dryness may cause nosebleeds or damage to gums and tooth loss.

Is Using the CPAP Humidifier Necessary?

There are certain times that you may not want to use the humidifier. For example, some people like to travel with a smaller device and choose to leave the humidifier portion at home.

In humid environments, it may not add much moisture to the air. Long-term users of CPAP may no longer feel like they need it. Moreover, many experienced users who have been using these devices for a decade or more may never have used a humidifier as part of their therapy.

There is a certain inconvenience in using a humidifier. It needs to be cleaned to prevent discoloration and reduce the risk of infection and mold exposure. It has to be filled up every night or two with fresh water, and if you are crawling into bed, this may be the last thing that you want to remember to do. Depending on its design, and the amount of light in your bedroom at bedtime, it may be hard to fill without spilling. It may seem like more of a hassle than it is worth. Without heated tubing, a heated humidifier may also cause condensation to form in the tubing and lead to sleep disruption due to noise or water splashing into the mask.

How to Stop Using the CPAP Humidifier

If you have decided you don’t want to use your CPAP’s humidifier, you may have a few options depending on your device model.

You may be able to simply remove it from the blower component and attach your tubing directly to the outlet from the blower. In newer models, such as ResMed’s AirSense series, you can simply turn the humidifier’s heating element and the heated tubing off. This can be deactivated within the patient settings menu. The air can then pass through without smells developing from a heated, dry and empty chamber.

You may discover that you develop more dryness once you stop using your humidifier. If you notice a dry mouth or nosebleeds, you could consider using saline rinses or sprays. Alternatively, you can simply resume use of the humidifier. You may discover that there are certain times of the year, or certain environments, when you want to use it and other times when you can take a break from it.

If you have any persisting problems, speak with your sleep specialist about options to optimize your therapy.


Kryger, M.H. et al. "Principles and Practice of Sleep Medicine." ExpertConsult, 5th edition, 2011.

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