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. Then it grows and thrives.

Where does mold grow?

Mold lives in moist conditions where there is oxygen and other chemicals. Places mold may be found most often include:


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

  • Moist, shady areas


  • 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 healthcare provider for more information.

Online Medical Reviewer: Deborah Pedersen MD
Online Medical Reviewer: Jessica Gotwals BSN MPH
Online Medical Reviewer: Marianne Fraser MSN RN
Date Last Reviewed: 4/1/2022
© 2000-2024 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.