Wheeze: Differential Diagnosis

Wheeze is a continuous, musical, high-pitched sound, typically louder on expiration, though it may occur during inspiration. It results from airflow through narrowed intrathoracic small-to-medium airways, caused by:

• Bronchoconstriction

• Mucosal edema/inflammation

• Luminal obstruction (e.g., mucus, foreign body)

• Occasionally, dynamic airway collapse during exhalation

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Stridor, in contrast, is a predominantly inspiratory sound from upper airway obstruction (e.g., larynx, trachea).

While asthma and COPD are the most common causes in adults, wheeze is not pathognomonic of either. The differential diagnosis is broader in children due to congenital and infective causes.

Adult Wheeze: Differential Diagnosis