bronchospasm

Last reviewed 01/2018

Bronchospasm is the narrowing of bronchioles by the contraction of smooth muscle in their walls in response to a given stimulus. Suitable stimuli include asthma, upper respiratory tract infections and bronchitis.

Symptoms and signs of bronchospasm include:

• increased expiratory effort, inspiration often unchanged
• polyphonic expiratory wheeze

Bronchospasm may be classified as being reversible or irreversible according to the effect of bronchodilator drugs. However, even in the most severe 'irreversible' obstructive airways disease, airflow can often be improved by bronchodilators; a continuum exists.