Should You Use Distilled Water for a CPAP Machine?

Continuous Positive Airway Pressure (CPAP) therapy is a highly effective treatment for obstructive sleep apnea (OSA) and other sleep-related breathing disorders. CPAP machines deliver a steady flow of air pressure through a mask to keep the airway open during sleep. To ensure optimal performance and hygiene of the CPAP machine, it is essential to use the right type of water in the integrated humidifier, if applicable. Distilled water is commonly recommended for use with CPAP humidifiers, but is it necessary, and what are the benefits and potential risks? In this article, we explore the reasons behind using distilled water and alternative options for CPAP machine humidifiers.

The Purpose of Using Distilled Water in a CPAP Humidifier:

CPAP machines often come equipped with integrated humidifiers to add moisture to the air delivered through the mask. The air from the CPAP can be dry, which may cause dryness, irritation, or congestion in the airways and nasal passages. The humidifier helps alleviate these issues, making CPAP therapy more comfortable and tolerable for users.

Why Use Distilled Water in CPAP Machine?

Distilled water is water that has undergone a purification process to remove impurities and minerals. It is free from contaminants, such as bacteria, minerals, and chemicals, which can be found in tap water or other bottled waters. Using distilled water in the CPAP humidifier ensures that these impurities do not get into the machine’s reservoir or the air that the user breathes during therapy. As a result, distilled water helps maintain the cleanliness and longevity of the CPAP equipment.

Benefits of Using Distilled Water in CPAP Machine:

  1. Purity: Distilled water is the purest form of water available, free from impurities and minerals that can cause buildup or contamination in the CPAP humidifier.
  2. Reduced Risk of Bacterial Growth: The absence of minerals in distilled water helps minimize the risk of bacterial growth in the humidifier’s water reservoir.
  3. Minimal Scale and Deposits: Using distilled water can reduce the formation of mineral scale and deposits in the humidifier, which can prolong the life of the equipment.
  4. Hygiene: Distilled water promotes a cleaner and more hygienic CPAP therapy experience, reducing the risk of respiratory issues associated with contaminated water.

Alternatives to Distilled Water in CPAP Machine:

While distilled water is recommended for CPAP humidifiers, some alternatives can be used if distilled water is not readily available:

  1. Sterile Water: Sterile water for irrigation, available at pharmacies, is a viable alternative to distilled water. It is free from contaminants and safe to use in CPAP humidifiers.
  2. Filtered Water: If you have access to a high-quality water filter system that effectively removes impurities and minerals, filtered water can be considered. However, it may not be as pure as distilled water.

What to Avoid:

It is essential to avoid using tap water or spring water in CPAP humidifiers. Tap water contains minerals and chemicals that can lead to mineral deposits, bacterial growth, and potential contamination of the equipment and air delivered during therapy.

What Happens If You Use Tap Water in Your CPAP Machine?

Using tap water in your CPAP machine’s humidifier can lead to several potential issues and risks, as tap water contains minerals, chemicals, and impurities that may negatively impact the equipment and your health. Here are some of the consequences of using tap water in your CPAP machine:

  1. Mineral Buildup: Tap water often contains minerals like calcium and magnesium. Over time, these minerals can accumulate inside the water reservoir and humidifier chamber, leading to mineral deposits or scale. This buildup can hinder the proper functioning of the humidifier, affect its performance, and reduce the efficacy of the CPAP therapy.
  2. Bacterial Growth: Tap water is not sterile and may contain bacteria or other microorganisms. When exposed to the warm and moist environment of the CPAP humidifier, these microorganisms can multiply and lead to bacterial growth. Breathing in air with bacterial particles can potentially cause respiratory issues or exacerbate existing conditions.
  3. Contamination of Airway: As the CPAP machine delivers air through the mask, any contaminants in the water may be released into the air stream. Breathing in contaminated air may lead to respiratory irritation, sinus issues, or other health problems, particularly for individuals with sensitivities or compromised immune systems.
  4. Unpleasant Odors: Bacterial growth in the humidifier can produce unpleasant odors that may be noticeable during CPAP therapy, affecting the user’s comfort and compliance with treatment.
  5. Equipment Damage: The mineral deposits and bacterial growth resulting from using tap water can damage the CPAP equipment. Scale and buildup in the water reservoir or tubing may cause blockages, leaks, or malfunctions, reducing the lifespan of the machine.
  6. Reduced Humidification Effect: The presence of impurities in tap water can affect the humidification process, leading to inconsistent or insufficient moisture delivery. This may result in discomfort and dryness in the airways during CPAP therapy.

Cleaning and Maintenance:

Regardless of the type of water used, proper cleaning and maintenance of the CPAP humidifier are essential. Follow the manufacturer’s guidelines for cleaning and disinfecting the equipment regularly to prevent mold, bacteria, and mineral buildup.

Tips for Traveling With Your CPAP Machine

Traveling with a CPAP machine can seem daunting, but with some planning and preparation, it can be a smooth and stress-free experience. Whether you’re going on a short weekend trip or an extended vacation, here are some tips to make traveling with your CPAP machine easier and more convenient:

  1. Check Airline Guidelines: If you’re flying, check the specific guidelines and policies of your airline regarding traveling with medical equipment. Most airlines allow CPAP machines as carry-on items, but it’s essential to be aware of any size or weight restrictions and any required documentation, such as a doctor’s letter or a medical equipment tag.
  2. Carry a Travel-Friendly CPAP Machine: Consider investing in a travel-sized CPAP machine, which is often smaller, lighter, and more portable than standard models. Travel CPAP machines are designed for ease of use during travel and may have additional features like universal power compatibility and optional battery operation.
  3. Protect Your CPAP Machine: Use a durable carrying case or travel bag to protect your CPAP machine during transportation. Many CPAP manufacturers offer specific travel cases designed for their machines. A padded case will safeguard your equipment from bumps and scratches.
  4. Pack Spare Supplies: Bring extra CPAP supplies, such as mask cushions, tubing, and filters, to ensure you have everything you need for the duration of your trip. While you can purchase supplies at your destination, having backups is helpful in case of emergencies or unforeseen circumstances.
  5. Universal Power Adapter and Surge Protector: If you’re traveling internationally or to a different region with different electrical outlets, bring a universal power adapter that is compatible with your CPAP machine’s power cord. Also, consider using a surge protector to protect your equipment from voltage fluctuations.
  6. Battery Backup: If you anticipate power outages or unreliable power sources during your travel, consider investing in a battery backup specifically designed for your CPAP machine. Portable battery packs can provide hours of power and ensure continuous therapy even without a stable power source.
  7. Prep Your CPAP Machine: Before your trip, clean and sanitize your CPAP machine, mask, and accessories thoroughly. Ensure that your water reservoir is empty to prevent leaks during travel. If your machine has a humidifier, consider using it without water during your trip to reduce the risk of spills.
  8. Inform Accommodations: If you’re staying in a hotel or other accommodation, inform them in advance that you will be using a CPAP machine during your stay. They may be able to provide you with a power outlet near your bed for convenience.
  9. Carry Necessary Documentation: Bring a copy of your CPAP prescription or a letter from your healthcare provider explaining your need for the equipment. Some airlines or transportation authorities may require this documentation.
  10. Keep Essentials in Your Carry-On: Always keep your CPAP machine and essential supplies in your carry-on bag during flights. This way, you’ll have them with you in case your checked luggage is delayed or lost.

By following these tips and planning ahead, you can ensure a comfortable and successful travel experience with your CPAP machine. Don’t let your sleep apnea prevent you from enjoying your adventures; with your CPAP machine by your side, you can rest easy and wake up refreshed while traveling.


Using distilled water in a CPAP humidifier is generally recommended for its purity, reduced risk of bacterial growth, and minimal mineral deposits. However, if distilled water is unavailable, alternatives like sterile water or filtered water can be used. Regardless of the water type, regular cleaning and maintenance of the CPAP humidifier are crucial for ensuring a clean and hygienic therapy experience. If you have any concerns or questions about using water in your CPAP humidifier, consult with your healthcare provider or CPAP equipment supplier for personalized guidance and recommendations.

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