Asthma is a chronic respiratory disease characterized by inflammation of the airways and lungs. During an asthma attack, the small airways leading to the air sacs in the lungs are constricted and inflamed, and as a result, less air is able to flow out of the lungs. Environmental exposures such as environmental tobacco smoke, dust mites, cockroach allergen, outdoor air pollution (e.g., ozone, particulate matter), pets, and mold are considered important triggers of an asthma attack. Read more