: characterized by an abnormal degree of responsiveness (as to a physical or emotional stimulus)
The biochemical barrage, which would be helpful were it directed at a foreign invader, provokes sustained inflammation of the airway lining. And, perversely, it makes the tissue much more sensitive (or hyperresponsive) to the original trigger. Stephen Hoffmann
Studies … have shown a hyperresponsive amygdala and impaired inhibition from the prefrontal cortex during tasks involving exposure to facial expressions, reactions to emotionally charged words, and interpersonal cooperation. John G. Gunderson
Measurements of airway hyperresponsiveness, although not sufficiently sensitive or specific to provide a definite diagnosis of asthma, are closely correlated with clinical assessments of the presence and severity of the disease. M. R. Sears et al.