Mold Allergy

Reviewed by Gabriela Pichardo on November 14, 2020

If you're allergic to mold, you've probably already noticed: It can be tough to avoid the stuff. It doesn't just hide in dark, damp basements. It can also grow on your bathroom tiles or around your windows.

You can find it outside too, on leaves and rotting wood, and inside in damp basements. And you can bring it into your home on your shoes, where it settles in on the carpet.

When you come in contact with mold, you may get symptoms like a runny or stuffy nose and itchy, watery eyes. And if you don't get it treated, it can sometimes lead to more serious health problems.

How It Causes Allergies

Mold is a fungus with a big job in the natural world: It breaks down dead plant matter. It spreads through tiny spores that can cause an allergic reaction, but only a few types bring on allergies.

How to Tell if You're Allergic

The only way you can know for sure is to see an allergist. They'll ask about your symptoms and what seems to trigger them. If they think you have a mold allergy, they'll probably do tests to confirm it.


When Mold Allergies Occur

Although they happen any time of year, allergies to outdoor mold can be worse in summer and fall. They can be especially bad when wet leaves sit around in piles.

How to Prevent Symptoms

To avoid problems from mold that's outside:

  • Stay inside when mold counts are high.
  • Keep wet leaves away from your home. Clean gutters.
  • Get rid of standing water in your yard.

To keep mold allergies away when you're inside your home:

  • Take off your shoes at the door.
  • Clean your bathroom often with bleach and get rid of soap scum, which can harbor mold.
  • When you shower, open a window or run an exhaust fan.
  • Fix any leaks right away. Dry wet areas within 48 hours to prevent the fungus from growing.
  • Run a dehumidifier in damp basements or other rooms.
  • Use a vacuum with a HEPA filter.

To Treat Symptoms

WebMD Medical Reference



American Academy of Allergy, Asthma & Immunology: "Mold Allergy."

Asthma and Allergy Foundation of America: "Mold Allergy."

Derek K. Johnson, MD, allergist in Fairfax, Va.; medical advisor, Asthma and Allergy Foundation of America.

© 2020 WebMD, LLC. All rights reserved.