Causes, Symptoms, and Advice for Mold Allergies

More mold. More allergies.

A woman wearing plastic gloves, cleans her counter tops.

Mold is a diverse and widespread group of fungi that lives just about anywhere. Certain types can cause allergic reactions and tough allergy symptoms.

In this page you will find information about

Fungus among us all year long

Mold and mildew are tiny fungi. They can live anywhere at any time of the year. So if you have persistent allergic symptoms that occur through several seasons, you might be allergic to mold.¹

There are hundreds of types of molds, but not all of them cause allergy symptoms. The most common allergy-causing molds include Alternaria, Aspergillus, Cladosporium, and Penicillium.²

Places where mold grows

Molds thrive in many environments, both indoors and outdoors. They flourish in damp, humid dwellings. Four primary things contribute to mold growth:²

  • Air
  • Appropriate temperature
  • Moisture
  • Food

Mold allergy causes and symptoms

Molds live everywhere, and they have spores. When the spores are disturbed, either by touch or air currents, they can spread rapidly. They flow around in the air — and cause allergic reactions when inhaled. When you inhale mold spores, your immune system treats it as an allergen and releases allergic antibodies to fight it off.¹,²

Typical allergic symptoms like sneezing, watery eyes, and runny nose are all ways your body rids itself of allergens.3

Tips to minimize mold exposure.

It’s impossible to to avoid all allergens, but there are a few things you can do to avoid mold:¹,,

  • When you’re inside
    • Keep doors and windows shut
    • Use dehumidifiers
    • Run an air conditioner with certified asthma and allergy friendly filters
    • Ensure there are no leaks or other causes of damp areas.
  • When you’re outside
    • Avoid outdoor activities early in the morning or late in the evening, when mold spore counts are high
    • Wear a dust mask when cutting grass, digging around plants, picking up leaves, and disturbing other plants
    • Shower after being outdoors
  • Start taking medications as soon as you notice allergy symptoms
  • Speak to your doctor for more information on allergies
A woman wears gloves while cleaning the inside of her windows

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Allegra® helps you live your best life by relieving many common allergy symptoms. If you experience sneezing, runny nose, itchy or watery eyes or an itchy nose and throat, nasal congestion, sinus congestion and pressure, or swelling of nasal passages, Allegra® has products that can help. Now you can live your greatness — everywhere.

No matter which product you choose, you can feel good knowing Allegra® is the #1 allergist-recommended medicine brand for non-drowsy relief.‡ 

Find the Allegra® product that’s right for you


  1. Asthma and Allergy Foundation of America, Editors. Mold Allergy, Asthma and Allergy Foundation of America (,


  2. American Academy of Allergy, Asthma, and Immunology, Editors. Mold Allergy, American Academy of Allergy, Asthma, and Immunology (,


  3. Andrew Moore, MD, FAAAAI, Reviewer. Outdoor Allergens, American Academy of Allergy, Asthma & Immunology (,

    September 28, 2020

  4. Jonathan Corren, MD. Allergic rhinitis: Treating the adult, The Journal of Allergy and Clinical Immunology,

    June 1, 2000

  5. Asthma and Allergy Foundation of America, Ed. Control Allergens to Improve Indoor Air Quality, Reviewed by Medical Scientific Council,


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