Bronchial hyperresponsiveness
Bronchial hyperresponsiveness (or other combinations with airway or hyperreactivity) is a state characterised by easily triggered bronchospasm (contraction of the bronchioles or small airways).
Bronchial hyperresponsiveness can be assessed with a bronchial challenge test. This most often uses products like methacholine or histamine. These chemicals trigger bronchospasm in normal individuals as well, but people with bronchial hyperresponsiveness have a lower threshold.