ICD-11

Asthma is a chronic inflammatory disorder of the airways in which many cells and cellular elements play a role. It is characterised by an increased responsiveness of the trachea and bronchi to various stimuli and manifested by a widespread narrowing of the airways that change in severity either spontaneously or as a result of therapy. This leads to recurrent episodes of wheezing, breathlessness, chest tightness, and coughing, particularly at night or in the early morning.

Exercise-induced bronchoconstriction (EIB) describes airway narrowing that occurs in association with exercise. EIB occurs in up to 90% of asthmatic patients and is estimated to occur in >10% of the general population. Recent reviews have identified asthma as a risk factor for sudden death and have reported many deaths that have been attributed directly to EIB.