The common causes of wheezing were: asthma (40.3%), bronchiolitis (36.8%), pneumonia (14.9%), gastroesophageal reflux (3.2%), tracheal stenosis (2.2%), foreign body aspiration (0.8%), mediastinal tumors (0.8%), vascular ring (0.5%), thymoma (0.3%) and Toxocara canis in the lung (0.3%).