Asthma is a common allergic respiratory condition which involves constriction as well as inflammation of airways lined with excessive amount of mucus in response to certain triggers.

• 哮喘是常见的过敏性呼吸道疾病，一般是因对某些外界物质的反应而致。患者呈现气管收缩，发炎及分泌过量黏液。