During an asthma attack smooth muscles located in the bronchioles of the lung constrict and decrease the flow of air in the airways. The amount of air flow can further be decreased by inflammation or excess mucus secretion.
Review Date 4/25/2023
Updated by: Charles I. Schwartz, MD, FAAP, Clinical Assistant Professor of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, General Pediatrician at PennCare for Kids, Phoenixville, PA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.