Bronchial asthma definition and diagnostic criteria 1. Definition: It is a chronic inflammatory disorder of the airways involving a variety of inflammatory cells and inflammatory mediators. This chronic inflammation leads to airway hyperresponsiveness (AHR), and when exposed to multiple irritants, airway obstruction and airflow restriction occur, with recurrent episodes of wheezing, shortness of breath, chest tightness, and coughing, often occurring or intensifying at night and/or early in the morning, and most children Most of the children can be relieved by treatment or resolve on their own. It is often not easily taken seriously by parents. 2. Diagnostic criteria: ① Recurrent episodes of wheezing, shortness of breath, chest tightness or cough, mostly related to exposure to allergens, cold air, physical or chemical stimuli, viral upper and lower respiratory tract infections, exercise, etc.; ② Scattered or diffuse expiratory phase croup and prolonged expiratory phase can be heard in both lungs during episodes; ③ Significant efficacy of bronchodilators; ④ Except wheezing, shortness of breath, chest tightness or cough caused by other diseases. cough.