Can a Humidifier Make You Sick?

By: Evan Scoboria, Last updated: June 28, 2023

Humidifiers can be a great addition to our homes, offering many health benefits, from alleviating dry skin to easing respiratory issues. However, like any device, they need to be used with care. If not appropriately maintained, a humidifier might become a source of health problems, potentially causing illness. This article aims to help you understand the risks associated with improper use of humidifiers and how to avoid them, so you can continue to reap the benefits of your humidifier without compromising your health. Let's delve into the circumstances where a humidifier could make you sick and how to prevent such situations.

Humidifier by Healthy House Plant

Can a Humidifier Make You Sick?

Regulating the air's moisture level can significantly improve our overall health and comfort, especially during the drier months of the year. However, like any other household device, their impact on our health can be twofold. While they offer numerous benefits, including relief from dry skin, allergy symptoms, and respiratory issues, improper use can lead to unwanted health complications.

Dirty Humidifier Hazards

Humidifiers can become a breeding ground for mold and bacteria if not correctly maintained. Here's how that happens and why it can be a problem.

When you use a humidifier, you're adding moisture to the air. That moisture can create an ideal environment for growing bacteria and mold. And here's the kicker: when the humidifier releases moist air, it can also disperse those microorganisms into your home environment. You could unknowingly inhale them, leading to respiratory issues, especially for those with weakened immune systems or pre-existing respiratory conditions.

Moreover, specific types of bacteria and molds are more likely to grow in humidifiers. For instance, 'Pink mold'—which, despite the name, is a type of bacteria called Serratia marcescens—is commonly found in damp environments, including humidifiers. It can cause respiratory, urinary, and gastrointestinal infections. 'Black mold,' or Stachybotrys chartarum, is another one that can grow in excessively humid conditions and may cause allergies and breathing problems.

These risks underline the importance of regular cleaning and maintenance of your humidifier. Use distilled or demineralized water instead of tap water, as fewer minerals can support microbial growth. Also, replace the water in your humidifier daily to avoid letting it sit and become stagnant, providing a ripe environment for bacteria and mold. Please regularly clean the entire humidifier, especially the tank, according to the manufacturer's instructions. These steps can help prevent mold and bacteria growth in your humidifier and keep your indoor air healthier, ensuring a safe sleeping and living environment.

Problems caused by over-humidification (e.g., respiratory issues, allergy triggers)

Over-humidification, or high indoor humidity levels, can trigger health problems, particularly for those with pre-existing respiratory conditions or allergies. Let's take a closer look at these issues.

  1. Respiratory Issues: Moist environments are perfect breeding grounds for harmful organisms like bacteria and fungi. When a humidifier makes the air excessively moist, it can promote the growth of these organisms. Breathing in this contaminated air can lead to respiratory infections and aggravate conditions like asthma. Excessive humidity can also lead to shortness of breath and difficulty breathing, especially in those with chronic obstructive pulmonary disease (COPD).

  2. Allergy Triggers: Over-humidification can be quite a problem for folks with allergies. Dust mites, one of the most common indoor allergens, thrive in high humidity. Likewise, mold growth, another significant allergen, is also encouraged by damp conditions. So, if you're cranking up your humidifier too high, you might be inadvertently causing an allergy flare-up.

  3. Skin Issues: While low humidity can dry your skin, excessive moisture isn't good for it. It can lead to sweaty and clammy skin, heat rash, and even worsen conditions like eczema.

  4. Cold and Flu: Some research suggests that high indoor humidity levels can increase the survival and transmission of viruses like the flu.

Remember, the goal is to strike a balance. The U.S. Environmental Protection Agency recommends keeping indoor humidity levels between 30% and 50% for optimal comfort and health. Monitoring your indoor humidity and adjusting your humidifier use accordingly is critical to avoiding the potential health problems caused by over-humidification.

Humidifier Fever

Humidifier fever, more officially known as "hypersensitivity pneumonitis," is a potentially severe illness that can be associated with the use of poorly maintained humidifiers.

This condition is a form of lung inflammation, explicitly targeting the tiny air sacs in the lungs, alveoli, and surrounding lung tissue. It's caused by an allergic reaction to inhaled dust, fungus, molds, or bacteria that may have been dispersed into the air by a dirty humidifier.

Symptoms can occur a few hours after exposure and mimic those of the flu, including fever, cough, shortness of breath, chills, body aches, and fatigue. However, unlike the flu, humidifier fever can clear up within a day or two once the person is no longer exposed to the particles from the humidifier.

However, it's important to note that prolonged or repeated exposure to these particles can lead to more severe conditions, like chronic hypersensitivity pneumonitis, which may cause permanent lung damage.

The key to preventing humidifier fever is to keep your humidifier clean. Regular maintenance is vital and includes tasks such as changing the water daily, cleaning the tank frequently, and replacing filters as the manufacturer recommends. These actions can significantly reduce the risk of bacteria and mold buildup in your humidifier, thereby minimizing the risk of humidifier fever.

Remember, a humidifier can be an excellent tool for maintaining comfortable and healthy indoor humidity levels, but like any appliance, it requires proper care to function safely and effectively.

The Benefits of Proper Humidity Levels

Proper humidity levels are crucial in maintaining a healthy home environment and directly influence our comfort and overall well-being. When the air is too dry, it can lead to many issues, such as dry skin, itchy eyes, and irritated sinuses. By adding moisture to the air, humidifiers can help alleviate these discomforts.

Adequate humidity levels can also assist in respiratory health. Dry air can dry out the mucous membranes lining your respiratory tract, leading to discomfort and making you more susceptible to infections. By promoting a well-lubricated respiratory system, humidifiers can help prevent these issues, relieving common cold symptoms and easing asthma or allergies.

Moreover, a well-humidified environment can help maintain the vitality of your skin and hair, preventing them from drying out and becoming brittle. It can also benefit your wooden furniture and houseplants by preventing them from drying out.

In short, maintaining the proper humidity level is more than just a matter of comfort. It's a crucial aspect of creating a healthy living environment. However, ensuring that your humidifier doesn't become a health hazard is equally essential. This brings us to some potential health risks associated with humidifier misuse, which we will discuss next.

Keeping Your Humidifier Clean and Effective

As mentioned earlier, dirty humidifiers can release harmful contaminants into the air, potentially leading to respiratory and other health problems. Regular cleaning and maintenance are essential to prevent the growth of mold, bacteria, and other harmful microorganisms.

Tips for Maintaining a Clean Humidifier

To ensure your humidifier remains clean and operates effectively, follow these tips:

  1. Please read the manufacturer's guidelines: Each humidifier may have specific cleaning and maintenance instructions, so looking at the user manual for proper care is essential.

  2. Empty and refill the water tank daily: Stagnant water can promote the growth of bacteria and mold. Empty the water tank daily and fill it with fresh, clean water.

  3. Clean the humidifier regularly: Depending on the manufacturer's recommendations, clean the humidifier's water tank, filter, and other components every one to two weeks. Use a solution of white vinegar and water to remove any mineral deposits or scale buildup.

  4. Replace filters as needed: If your humidifier has a filter, replace it according to the manufacturer's recommendations or when it becomes discolored or dirty.

  5. Monitor humidity levels: Use a hygrometer to measure the humidity in your home and adjust the humidifier settings accordingly to maintain an optimal humidity range.

  6. Store the humidifier properly when not in use: If you won't use it for an extended period, clean it thoroughly and store it in a cool, dry place to prevent mold and bacteria growth.

Frequently Asked Questions

Can a humidifier cause respiratory problems?
Yes, if misused. Overusing a humidifier can create a too-humid environment that may exacerbate respiratory conditions or cause wheezing and difficulty breathing, particularly for individuals with asthma or allergies.

How can a dirty humidifier impact my health?
A humidifier that isn't cleaned regularly can become a breeding ground for mold, bacteria, and other pathogens. When inhaled, these can be dispersed into the air, leading to various health problems, including allergies, asthma exacerbations, or even flu-like symptoms.

What is "humidifier fever," and how can I avoid it?
Humidifier fever, or hypersensitivity pneumonitis, is a lung inflammation caused by inhaling particles from a dirty humidifier. Regular cleaning and maintenance of your humidifier can help prevent this condition.

What are the signs that my humidifier is making me sick?
If you're experiencing symptoms such as a cough, chest tightness, fever, chills, or shortness of breath after using a humidifier, it may make you sick. If these symptoms persist, you should stop using the humidifier and consult a healthcare professional.

What should the humidity level be in my home to avoid getting sick?
The ideal humidity level for your home is between 30-50%. Humidity levels above 50% may encourage mold growth, dust mites, and other allergens.

How often should I clean my humidifier to ensure it doesn't cause health problems?
Most manufacturers recommend cleaning the humidifier at least once a week, but it could be more often depending on usage and water hardness. Always follow the manufacturer's instructions.

Can overuse of a humidifier cause allergies?
Yes, overuse of a humidifier can lead to excess moisture in your home, promoting mold growth and dust mites - common triggers for allergies.

Can a humidifier spread germs or bacteria?
If the humidifier isn't cleaned regularly or properly, bacteria and germs can grow in the reservoir and be dispersed into the air when the humidifier is in use.

How can I properly use a humidifier to ensure it doesn't make me sick?
The key to safe humidifier use is regular cleaning, ensuring the room's humidity level doesn't exceed 50%, and using distilled or demineralized water to prevent mineral deposits and microbial growth.

What type of humidifier is less likely to cause health issues?
All humidifiers, when maintained properly, can be used safely. However, evaporative and steam vaporizer humidifiers are less likely to disperse mineral deposits and bacteria into the air than ultrasonic or cool mist humidifiers. Please always follow the manufacturer's instructions for use and maintenance to ensure your safety.


Humidifiers can provide numerous health benefits, including alleviating dry skin and respiratory issues caused by low humidity. However, they can also pose risks if not properly maintained or used correctly. By keeping your humidifier clean, monitoring humidity levels, and following the manufacturer's guidelines, you can enjoy the benefits of a comfortable and healthy indoor environment without the risk of adverse effects. Remember that proper humidity management is essential for both your well-being and the well-being of your home.