This document discusses asthma, including what it is, common causes and symptoms, diagnosis, treatment, and classification. Asthma is a chronic non-infectious inflammation of the bronchus that is often caused by factors like smoke, environmental contaminants, allergens, infections, and obesity. Common symptoms include difficulty breathing, dry coughing, chest tightness, and wheezing. Diagnosis involves lung function tests and may include other tests. Treatment involves both non-pharmacological methods to prevent attacks and pharmacological therapies administered via inhalers or nebulizers. Asthma is classified based on the severity of symptoms as intermittent, mild persistent, moderate persistent, or severe persistent.