[Bronchial hyperreactivity. Definitions and history].

The various definitions that are proposed for bronchial hyper-responsiveness (BH) are discussed. The semantic problems related to these definitions are presented: 1) the translation of bronchial hyperresponsiveness into French can vary; 2) BH is not synonymous of abnormal contraction of airway smooth muscle; 3) there is also some confusion of BH with the clinical status of asthma, which is excessive. The authors also review the difficulties related to the purely operational character of the definition itself: 1) BH has a continuous distribution in a general population; 2) BH can be expressed by various indices; 3) stimuli to reveal BH are various; 4) there are various types of BH related to the causal conditions; 5) there are different sites of BH within the airways. The authors also review the historical background of BH with some emphasis on the contribution of French-speaking research workers.