OverviewBronchiolitis is an inflammation of the bronchioles (smaller airways that branch off the main airway) usually caused by a viral infection.
Review Date 2/15/2016
Updated by: Neil K. Kaneshiro, MD, MHA, Clinical Assistant Professor of Pediatrics, University of Washington School of Medicine, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.