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Allergens, chemicals and strong scents are common triggers for the almost 25 million Americans with asthma. But high humidity can be just as troublesome.

People with asthma have inflamed airways that are sensitive to things that may not bother other people. That’s why humidity, and all that comes with it, can be a problem for people with asthma.1 Here are some reasons why.

1. Humid air feels harder to breathe in. Some believe moist air is heavier and harder to breathe. Heat and humidity usually occur together. So when the air is harder to breathe, your body temperature can go up, causing you to sweat. This can lead to dehydration, which can make you breathe faster. All of this combined can trigger asthma symptoms.

Consider spending time outdoors in the mornings or evenings when heat and humidity levels tend to be lower. This can be especially important if you exercise outdoors.

2. Humidity can mean extreme temperatures. Since humidity usually is highest in the summer, extreme heat can aggravate your airways, just like extreme cold air can. Asthmatic lungs tend to be more sensitive to extreme temperatures.2

Sudden changes in temperature can affect your lungs too. If you’ve ever left a dry, cold air-conditioned building to go outside into hot, humid air, you know the change in air and temperature can be quite a shock. If you have asthma, the sudden change can actually cause an asthma attack.

3. Humidity can make air quality worse. Humid air alone is not all that triggers asthma attacks. Humidity can increase levels of mold, dust mites and ground-level ozone. All three are known to be asthma triggers.

Ozone, a gas that is a common air pollutant, irritates the airways and can make it harder for you to breathe deeply. Ozone levels can rise along with humidity, triggering asthma symptoms.

Mold and dust mites thrive in humid weather. If you have allergic asthma and have allergies to mold and dust, increases can cause symptoms. Mold can be a problem outside where leaves collect and in more tropical climates. An increase in indoor humidity can allow mold to grow in damp areas of your home like in bathrooms.

Dust mites are more of a problem inside when humidity is high. If the humidity in your home is higher than 50 percent, dust mites can multiply. Running your air conditioner or a dehumidifier can help you balance the humidity in your home.

You can’t always control your exposure to humidity, but there are many treatment options to help you manage asthma symptoms humidity may cause. See a board-certified allergist to help you come up with an asthma management plan.

Medical Review July 2017.

1. Hayes, D., Collins, P. B., Khosravi, M., Lin, R., & Lee, L. (2012). Bronchoconstriction Triggered by Breathing Hot Humid Air in Patients with Asthma. American Journal of Respiratory and Critical Care Medicine,185(11), 1190-1196. doi:10.1164/rccm.201201-0088oc

2. D’Amato, G., Vitale, C., De Martino, A., Viegi, G., Lanza, M., Molino, A., … D’Amato, M. (2015). Effects on asthma and respiratory allergy of Climate change and air pollution. Multidisciplinary Respiratory Medicine, 10, 39.

It is important to stay up-to-date on news about asthma and allergies. By joining our community and following our blog, you will receive news about research and treatments. Our community also provides an opportunity to connect with other patients who manage these conditions for support.


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Why is it politicians and stakeholders do not appear to be indoor monitoring  “indoor relative humidity”, etc existing inside schools, workplace, and homes that directly contribute toward inflation for everyone——including incurable real estate “over time”..

3 Indoor Monitoring Examples -

Tom Martin III

Very informative! I've just read the related article about humidity recently We don't live in a wet climate, and my son suffered because of dry air. We bought an ultrasonic humidifier to help him breathe easier, but at that time we hadn't known that the humidity level should be 40-45%. So the humidity in our room was around 55%, and my son’s health has not only not improved, but has also worsened. Thanks to our Dr, he explained to us how much does a humidity level should be. Now he feels better, we maintain 40% humidity in his room. Poor ones, who live in wet hot countries.

P.S.We bought a hygrometer for checking a humidity level.


Humidity does make me feel like the air is heavier/denser to breath and therefore my asthma feels worse when it is humid especially in the hot weather.  

Interesting points in the article.  Good reminder about how the changes from going between hot and cold air temperatures can cause problems.

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