types

Last reviewed 01/2018

Wheezes are described in terms of:

• frequency: high- or low-pitched
• duration: long or short
• location in respiratory cycle: inspiratory or expiratory
• number: single - monophonic - or multiple - polyphonic

A monophonic wheeze consists of a small number of notes starting and ending at different times. It may be caused by asthma, by a large tumour occluding a major bronchus (often positionally dependent), and interstitial fibrotic conditions (characteristically within the lower lobes).

Polyphonic wheezes are composed of many discordant frequencies starting and finishing in tandem. It implicates compression of central bronchi. It is characteristic of chronic obstructive lung disease, when it occurs at rest in expiration. It is mimicked by a rapid rate of flow during a forced expiratory ejection.