OverviewBronchiolitis is an inflammation of the bronchioles (smaller airways that branch off the main airway) usually caused by a viral infection.
Update Date 7/10/2015
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, Bethanne Black, and the A.D.A.M. Editorial team.