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.

Date Last Reviewed: 12/31/2024

© 2000-2026 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.
stethoscope icon

Personalized care starts with the right provider

Search by specialty, location, and more.

FIND A DOCTOR
Related Articles
Read article
Allergies
Allergens: Dust and Dust Mites

Dust mites are microscopic organisms that can live throughout homes and businesses. Read on to learn more.

Read article
Allergies
Allergens: Pollen

Pollen is the most common cause of hay fever. Read on for more information--and helpful tips for reducing the effects of hay fever during pollen season.

Read article
Allergies
Allergies and the Immune System

Most allergic reactions are a result of an immune system that responds to a "false alarm."

Read article
Wellness
Milk Allergy Diet

Detailed information on milk allergy, a type of food allergy. Learn about how to read a label for a milk-free diet, other possible sources of milk, and tips for eating out.