A high-pitched, musical, lung sound heard best during expiration. Wheeze can be heard in conditions, such as, Asthma, COPD, Bronchiolitis, Bronchitis, Emphysema, Heart failure, Lung Cancer, and Pneumonia.
A wheeze is produced by airflow through a narrowed or compressed airway that becomes turbulent, causing vibration of the airway walls. The airway narrowing may be caused by bronchoconstriction, mucosal edema, or partial obstruction by a tumor or foreign body. The quality and duration of wheezing depends on where in the airways the obstruction is located and how severe the narrowing. For example, wheezing from asthma is due to narrowing of the lower airways whereas with malignancies the obstruction is usually in the upper, more proximal airway.