Final answer:
Asthma is a chronic inflammatory disease of the airways, causing swelling and narrowing, leading to difficulty breathing and other symptoms.
Step-by-step explanation:
Asthma is a chronic inflammatory disease of the airways in the lungs, in which the airways periodically become inflamed. This causes swelling and narrowing of the airways, often with excessive mucus production, leading to difficulty breathing and other symptoms. Asthma attacks are triggered by allergens, air pollution, or other factors.