The most common asthma triggers include: Substances that cause allergies (allergens) can trigger asthma. If you inhale something you are allergic to, you may experience asthma symptoms. It is best to avoid or limit contact with known allergens to decrease or prevent asthma episodes.
Indoor Asthma Triggers. Some of the most common indoor asthma triggers include environmental tobacco smoke (secondhand smoke), dust mites, mold, cockroaches and other pests, and household pets. Visit these Web sites to learn about asthma triggers and how to reduce your exposure to them.
It isn’t clear why some people get asthma and others don’t, but it’s probably due to a combination of environmental and genetic (inherited) factors. Exposure to various irritants and substances that trigger allergies (allergens) can trigger signs and symptoms of asthma. Asthma triggers are different from person to person and can include: