High and low humidity not good for asthma

by John Bottrell Health Professional

It's roasting outside, yet the
beaming down on Jake Gallant as
rests in
his beach chair feels great.
The warm breeze
wafting over his bare
feels great too.
his eyes and listens to the soporific, relaxing sound of waves.

"This is the kind of weather I'd like to pack into a bottle to open in the dog days of winter," he thinks, "except for one thing:
the dog gone humidity make the air
heavy to breath."

As anyone with a chronic lung disease will attest to, humidity can make air harder to inhale.
Although, as the
Asthma Educator's Handbook
notes, humidity alone cannot trigger an asthma attack.

That in mind, here is the latest wisdom regarding high humidity and asthma:

  • An
    ARIC report notes that
    with a relative humidity lower than 50% had fewer "rates of asthma."

  • The report also states
    that "every 10% increase in indoor humidity was associated with a 2.7% increase in the prevalence of asthma."

  • The American Academy of Allergy Asthma and Immunology (AAAAI) states
    high humidity levels also have a tendency to be harboring grounds for fungus and molds that might bother asthmatics.

  • When
    humidity is greater than 50%, the amount of dust mites in the air is increased.

So now that you know high humidity is not particularly good for asthma, what can you do about it?

According to the American Lung Association, "Air-conditioning can help. It allows windows and doors to stay closed. This keeps some pollen and mold spores outside. It also lowers indoor humidity. Low humidity helps to control mold and dust mites."

Another solution, if you can't afford air conditioning, is to have a dehumidifier in your home.
This is a little more work as you have to empty it once or twice a day, but it works to keep the humidity down.

Years ago doctors recommended asthmatics move to warmer, and drier climates like that of Arizona.
Today doctors no longer recommend this because of technology like dehumidifiers and airconditioners that allow asthmatics to control the climate in their homes, and modern medicines that allow for better control of asthma.

While we see why high levels of humidity are bed for asthmatics, it's also important to make sure you don't make the air too dry. I say this because new research shows that air that is too dry is not good for asthma either. AAAAI.org reports that if the relative humidity is less than 15%, this may trigger an excessive cough for asthmatics. Low humidity can irritate asthma because it dries out the mucous membranes lining your airway, which are your body's natural defenses against foreign bodies such as viruses and bacteria. Thus, dry mucous membranes make you more susceptible to catching diseases like the common cold virus or influenza. If that's not enough, dry mucous membranes also have the tendency to aggravate allergy symptoms.

In the winter months, the air tends to get very dry, the humidity too low. You can tell when your skin and lips become itchy and chapped and your throat, dry. If the humidity gets too low you can use a humidifier.

Perhaps you're thinking,
"How can I win?
I can't have humidity too high and I can't have it too low either."

The answer, according to AAAAI.org, is for "asthmatic patients to aim for a 'happy medium' relative humidity in their homes, monitoring their home humidity regularly with a reliable gauge."

The Center for Disease Control and Prevention recommends humidity be set between 35% and 50%.

I'm not endorsing a prouct here, but you can use a humidity monitor like some of the ones
at Amazon.com

The majority of us asthmatics should be able to control our asthma just fine simply by keeping in touch with our doctor and by making sure we take our asthma meds exactly as prescribed. With well controlled asthma, we should all be able to get outside and enjoy the warm, humid, summer weather like Jake Gallant.

Yet, if high humidity continues to pose a problem for your breathing this summer, setting up your home with air conditioning is a great option. You can close all the windows, crank up the air, and enjoy the cool, refreshing, easy-to-breathe air.

John Bottrell
Meet Our Writer
John Bottrell

John Bottrell is a registered Respiratory Therapist. He wrote for HealthCentral as a health professional for Asthma and Chronic Obstructive Pulmonary Disease (COPD).