临床上表现为反复发作性的喘息、呼气性呼吸困难、胸闷、咳嗽，常在夜间和或清晨发作，症状可自发缓解或经治疗后缓解。
Its clinical symptoms are recurrent episodes of wheezing , expiratory dyspnea , chest tightness and cough , which usually occur at night and or in the morning , and could be released spontaneously or with appropriate treatment .
呼气性呼吸困难