What causes asthma?
Allergens, irritants, respiratory infections and/or exercise can trigger asthma symptoms. Asthma is often placed in different categories according to symptom “triggers.”
Allergic asthma is triggered by allergic reactions to allergens such as pet dander, dust or dust mite, mold or pollen.
Seasonal asthma is triggered by seasonal allergic reactions to allergens such as trees, grasses or weeds.
Non-allergic asthma is triggered by irritants in the air that you breathe such as tobacco smoke, wood smoke, room deodorizers, fresh paint, perfume, etc.
Exercise-induced asthma is triggered by exercise or physical activity.
Nocturnal asthma can occur in a patient with any type of asthma, though the asthma symptoms will increase or worsen at night.