Can a Humidifier Make You Sick Illustration

Can a Humidifier Make You Sick? – Explained (2024)

by | Updated: May 16, 2024

In recent years, humidifiers have become increasingly popular as a go-to solution for combating dry indoor air, providing relief for ailments such as allergies, dry skin, and respiratory issues.

However, there is a growing concern that these seemingly innocuous devices could potentially have negative impacts on our health.

The question arises: Can a humidifier make you sick?

In this article, we will delve into the science behind humidifiers and explore the potential risks associated with their use.

We’ll also offer practical guidance on how to maximize the benefits and minimize the risks of using these devices in your home or workplace.

Is Your Humidifier Making You Sick?

Yes, your humidifier could potentially make you sick if it is not properly maintained, leading to the growth of mold, bacteria, or other harmful microorganisms in the water reservoir. To prevent this, it is essential to regularly clean your humidifier, follow the manufacturer’s guidelines, and maintain optimal humidity levels in your living spaces.

What Causes Humidifier Sickness?

Humidifier sickness is primarily caused by improper use, inadequate maintenance, and poor hygiene practices associated with humidifiers.

Some specific factors that can lead to humidifier sickness include:

  • Contaminated water reservoirs: Allowing water to sit for extended periods, using contaminated water, or not cleaning the humidifier regularly can promote the growth of bacteria, mold, and other harmful microorganisms.
  • Over-humidification: Excess humidity in the air (above 60%) creates a conducive environment for mold, mildew, and dust mites to thrive, which can exacerbate allergies and respiratory issues.
  • Mineral buildup: Using hard water in a humidifier may lead to the release of mineral particles into the air, which can cause respiratory irritation when inhaled.
  • Inadequate cleaning: Infrequent or improper cleaning of the humidifier may result in a buildup of mineral deposits, mold, and bacteria, which can be dispersed into the air when the humidifier is in use.
  • Ignoring manufacturer guidelines: Failing to follow the manufacturer’s instructions for cleaning, filter replacement, and usage can contribute to poor performance and increased health risks.

Humidifier Sickness Symptoms

While humidifiers can provide numerous benefits to users, improper use or maintenance can lead to potential health issues.

These illnesses are often referred to as “humidifier sickness” and can manifest through a variety of symptoms. Some common humidifier sickness symptoms include:

  • Respiratory issues: Over-humidified air can exacerbate existing respiratory conditions, such as asthma or allergies. Symptoms may include increased coughing, wheezing, shortness of breath, or nasal congestion.
  • Allergic reactions: Mold and bacteria that can grow in a poorly maintained humidifier can trigger allergic reactions, such as sneezing, itchy eyes, runny nose, and skin irritation.
  • Headaches and fatigue: Excess humidity may lead to headaches or feelings of fatigue, possibly due to the damp conditions promoting the growth of mold and dust mites in the environment.
  • Sinus infections: Prolonged exposure to a contaminated humidifier can increase the risk of sinus infections, characterized by facial pain, nasal discharge, and headache.
  • Flu-like symptoms: In some cases, humidifier sickness may present with flu-like symptoms, such as fever, chills, and body aches. This could be due to the inhalation of harmful microorganisms released by a contaminated humidifier.

It is important to recognize these symptoms and address the underlying issue, which may be linked to your humidifier’s use or maintenance.

Consulting with a healthcare professional and ensuring proper humidifier upkeep can help mitigate these risks and promote a healthy living environment.

How to Avoid Humidifier Sickness

To avoid humidifier sickness and maintain a healthy indoor environment, consider implementing the following practices:

  • Regular cleaning: Clean your humidifier as recommended by the manufacturer, usually at least once a week. This ensures that mold, bacteria, and mineral deposits do not accumulate in the device.
  • Use distilled or demineralized water: Avoid using tap water, as it can contain minerals that promote bacterial growth and can be dispersed into the air. Instead, use distilled or demineralized water to minimize mineral buildup and reduce the risk of respiratory irritation.
  • Maintain optimal humidity levels: Aim to keep indoor humidity levels between 30-50%, as recommended by the Environmental Protection Agency (EPA). Use a hygrometer to measure humidity and adjust your humidifier settings accordingly.
  • Replace filters and wicks regularly: Follow the manufacturer’s guidelines on replacing filters and wicks to ensure optimal performance and reduce the risk of contamination.
  • Avoid over-humidification: Over-humidification can promote the growth of mold, mildew, and dust mites. Be mindful of the room size and choose a humidifier with an appropriate capacity to prevent excessive humidity.
  • Proper storage: If you are not using your humidifier for an extended period, ensure that it is thoroughly cleaned, dried, and stored in a cool, dry place to prevent bacterial growth.
  • Ventilation: Ensure that your living spaces are well-ventilated to promote healthy air circulation and prevent the buildup of excess moisture.
  • Consider using a humidifier with a built-in humidistat: A humidistat can automatically adjust the humidity output to maintain desired levels, preventing over-humidification.

By following these recommendations, you can minimize the risk of humidifier sickness and create a more comfortable and healthier living environment.

What is Humidifier Fever?

Humidifier fever, also known as “humidifier lung,” is a respiratory illness caused by the inhalation of airborne contaminants, such as bacteria, mold, or endotoxins, that may be released from contaminated humidifiers.

This condition is a type of hypersensitivity pneumonitis, an inflammatory lung disease resulting from an immune response to inhaled allergens or irritants.

Symptoms of humidifier fever can resemble those of the flu or pneumonia and may include:

These symptoms typically appear several hours after exposure to the contaminated air and may resolve spontaneously within a day or two after leaving the affected environment.

However, repeated exposure to these contaminants can lead to long-term lung damage and chronic respiratory issues.

To prevent humidifier fever, it is essential to properly maintain your humidifier, regularly clean the device, use distilled or demineralized water, and avoid over-humidification in your living spaces.

How Long Does Humidifier Fever Last?

Humidifier fever typically lasts for a short duration, with symptoms often resolving spontaneously within a day or two after leaving the contaminated environment or ceasing the use of the humidifier.

The duration of the fever can vary depending on the individual’s immune response, the level of exposure to the contaminants, and the severity of the symptoms.

However, if the exposure to the contaminated air persists, the symptoms may become more persistent and even lead to long-term lung damage or chronic respiratory issues.

Note: If you suspect you are experiencing humidifier fever, it is important to promptly address the issue by cleaning and maintaining the humidifier properly, adjusting humidity levels, and seeking medical attention if symptoms do not improve or worsen over time.


What is the Difference Between Humidifier Sickness and Humidifier Fever?

Humidifier sickness refers to a range of symptoms and health issues that may arise due to improper use or maintenance of a humidifier, leading to the growth of bacteria, mold, or other harmful microorganisms.

Symptoms can include respiratory issues, allergic reactions, headaches, sinus infections, and flu-like symptoms.

On the other hand, humidifier fever is a specific and rare respiratory illness, a form of hypersensitivity pneumonitis, caused by the inhalation of airborne contaminants released by a contaminated humidifier.

Related: Can Mold Grow in Your Lungs?

How Do I Know if My Humidifier is Making Me Sick?

If you are experiencing symptoms such as coughing, wheezing, nasal congestion, itchy eyes, skin irritation, headaches, or flu-like symptoms, and they seem to worsen when you are using your humidifier, there is a possibility that your humidifier could be making you sick.

If you suspect this is the case, ensure that you clean and maintain the humidifier properly, adjust humidity levels, and consult with a healthcare professional if symptoms persist.

How Often Should I Clean My Humidifier?

Ideally, you should clean your humidifier at least once a week, or as recommended by the manufacturer. Regular cleaning helps prevent the growth of bacteria, mold, and other harmful microorganisms, reducing the risk of humidifier sickness.

Can I Use Tap Water in My Humidifier?

It is generally not recommended to use tap water in your humidifier, as it can contain minerals that promote bacterial growth and can be dispersed into the air.

Instead, use distilled or demineralized water to minimize mineral buildup and reduce the risk of respiratory irritation.

What is the Ideal Indoor Humidity Level?

The Environmental Protection Agency (EPA) recommends maintaining indoor humidity levels between 30-50%. This range helps prevent the growth of mold, mildew, and dust mites while providing a comfortable environment for occupants.

Can I get Humidifier Fever From an Ultrasonic or Cool Mist Humidifier?

Although the risk is generally lower, it is still possible to develop humidifier fever from an ultrasonic or cool mist humidifier if it is not properly maintained and cleaned.

Regardless of the type of humidifier, regular cleaning, proper use, and maintenance are essential for reducing health risks.

Final Thoughts

As previously mentioned, a humidifier can make you sick if it is not properly maintained. While humidifiers can provide numerous benefits, such as relieving dry skin, reducing allergy symptoms, and preventing respiratory infections, they can also pose health risks if not used correctly.

Bacteria and fungi can grow and spread through mist produced by the humidifier, leading to respiratory problems and allergic reactions.

To avoid these risks, it is important to clean and maintain your humidifier regularly, use distilled water, and appropriately set the humidity levels.

With proper care, a humidifier can be a useful tool for improving indoor air quality and promoting overall health and well-being. Thanks for reading, and, as always, breathe easy, my friend.

John Landry, BS, RRT

Written by:

John Landry, BS, RRT

John Landry is a registered respiratory therapist from Memphis, TN, and has a bachelor's degree in kinesiology. He enjoys using evidence-based research to help others breathe easier and live a healthier life.


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