These substances are known as allergens.
However, not everyone with asthma has allergies, and vice versapeople with allergies dont always have asthma.
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1.
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Pollen
Trees, grass, and weeds release tiny pollen particles into the air to reproduce.
Mold Spores
Mold sporesthrive in damp places like soil, leaves, and compost.
They spread through the air and can trigger symptoms, especially in humid or rainy weather.
To reduce exposure:
4.
Weather Changes
Heat (especially with high humidity) and rain can increase allergens like mold.
Animal Allergens
Animals can trigger asthma through allergens in dander and saliva.
To reduce exposure to outdoor animal allergens:
6.
Certain allergy apps can also provide real-time pollen counts and air quality alerts.
Sometimes, a primary care provider will refer you to an allergist.
Nonallergic Asthma Triggers
Allergens that cause an immune reaction can lead to allergic asthma.
Nonallergic asthma comes from irritants, which do not cause an immune response but can inflame the airways.
Work with a healthcare provider to develop an asthma action plan to avoid triggers and manage symptoms.
Check pollen and air quality reports, limiting your time outside on high-allergen days, or wearing a mask.
American College of Allergy, Asthma & Immunology.Allergic asthma overview.
2021;5:349-360. doi:10.5414/ALX02294E
deShazo RD, Kemp SF.Trigger avoidance in allergic rhinitis (beyond the basics).
In: Corren J, Feldweg AM, eds.UpToDate.
UpToDate; 2025
Asthma and Allergy Foundation of America.Mold allergy.
Centers for Disease Control and Prevention.Avoid bug bites.
Miller RL.Trigger avoidance in asthma (beyond the basics).
In: Bochner BS, Dieffenbach P, eds.UpToDate.UpToDate; 2025.
