What is the definition of asthma according to the Expert Panel Report 3 (EPR3) of the National Asthma Education and Prevention Program (NAEPP)?

Asthma is a chronic inflammatory disorder of the airways that involves many cells and cellular elements, particularly mast cells, eosinophils, T lymphocytes, macrophages, neutrophils, and epithelial cells.
Asthma is a complex chronic disorder of the airways that is characterized by variable and recurrent symptoms, airflow obstruction, exaggerated bronchial response, and underlying inflammation.
Asthma is a respiratory disease that affects only the lungs and is caused by exposure to environmental factors such as pollution and smoking.