<unk>  (or other combinations with airway or hyperreactivity, BH used as a general abbreviation) is a state characterised by easily triggered bronchospasm (contraction of the<unk> es or small airways).<unk>  can be assessed with a<unk>  challenge test. This most often uses products like methacholine or histamine. These chemicals trigger bronchospasm in normal individuals as well, but people with<unk>  have a lower threshold.<unk>  is a hallmark of asthma but also occurs frequently in people suffering from chronic obstructive pulmonary disease (COPD). In the Lung Health Study,<unk>  was present in approximately two-thirds of patients with non-severe COPD, and this predicted lung function decline independently of other factors. In asthma it tends to be reversible with bronchodilator therapy, while this is not the case in COPD.<unk>  has been associated with gas cooking among subjects with the GSTM1 null genotype.
Bronchial hyperresponsiveness
Exercise-induced bronchoconstriction
Reactive airway disease
Hepatization of lungs
Pathophysiology of asthma
Air trapping
Sinus node dysfunction
Pulmonary hyperplasia