Causes

Mold

Choose a preferred language


What is mold?

Mold is a member of the fungus family. It's rarely killed by heat or cold exposure. Mold stays inactive (dormant) until a certain season, such as spring or fall, or when favorable environmental conditions appear. Then it grows and thrives.


Where does mold grow?

Mold lives in moist conditions where there is oxygen and material to feed on. Mold may be found both outdoors and indoors.

Outside, mold is most often found:

  • On dead or dying vegetation, such as rotting leaves and logs.

  • In moist, shady areas.

Inside, you may find mold in:

  • Damp basements and closets.

  • Bathrooms.

  • Food storage areas.

  • Refrigerators.

  • House plants.

  • Air conditioners and humidifiers.

  • Mattresses or upholstered furniture that is damp.

  • Garbage containers.


What is mold allergy?

Mold spores or fragments may be breathed in through the nose and into the lungs. In some people, they may cause allergic reactions or asthma.

There is no known relationship between an allergy to the mold Penicillium and an allergy to the antibiotic penicillin, which is made from the mold. Talk with your child's health care provider for more information.

© 2000-2025 The StayWell Company, LLC. All rights reserved. This information is not intended as a substitute for professional medical care. Always follow your healthcare professional's instructions.

Find a doctor that's right for you.

From routine check-ups to groundbreaking treatments and beyond, Crestner Health is here to help you live your healthiest life.

Search our doctors
Related Articles
Read article
Allergies
Latex Allergy

Symptoms of latex allergy include watery or itchy eyes, wheezing, hives, flushing or a skin rash, itching, or swelling.

Read article
Allergies
Causes of Nasal Allergies

Nasal allergies are most often caused by one or more of four kinds of allergens: pollen, dust mites, mold, and animals.

Read article
Allergies
Controlling Allergens: In the Home

Even a clean home can be full of allergens. Read on to see what you can do to cut down on allergens in each room of your home.

Read article
Allergies
When Your Child Has Anaphylaxis

Anaphylaxis is the most severe type of allergic reaction. It may happen from a few minutes to an hour or 2 after contact with an allergen. Anaphylaxis can cause the airways to swell, making it hard to breathe.