Causes & Triggers

Allergens

Some allergens, or substances that cause allergies, are more likely to trigger an asthma attack. Common allergens that may trigger asthma symptoms throughout the year include indoor allergens, such as dust mites, cockroaches, molds, and animal dander. Outdoor seasonal aeroallergens, such as tree, grass or weed pollens, and outdoor molds can also trigger asthma symptoms in older children and adults.