This document discusses several disorders that can cause alterations in pulmonary function in children. It describes disorders of the upper airways including croup, epiglottitis, tonsillitis, foreign body aspiration, and obstructive sleep apnea. Disorders of the lower respiratory tract are also outlined such as respiratory distress syndrome in newborns, bronchopulmonary dysplasia, various respiratory infections including pneumonia and bronchiolitis, aspiration pneumonitis, asthma, and cystic fibrosis. Acute respiratory distress syndrome and sudden infant death syndrome are also briefly covered.