They pass bad days with trepidation, because if asthma (a severe constriction of the bronchial muscles that can lead to asphyxiation) strikes, it can be fatal if they don't receive medical attention in time.
嚴重者日子更是過得戰戰兢兢，萬一哮喘（即氣喘，氣管平滑肌劇烈收縮，以致氣管孔徑狹窄無法呼吸）發作，還可能因送醫不及而致命。