Generally, asthma can be divided into two types( external caused and internal caused asthma): most external caused asthma cases are intaking allergy source, but there is unknow reason for internal caused asthma.

• 气喘可大略分为外因性气喘及内因性气喘两大类：外因性气喘多因吸入过敏原所引起，而内因性气喘则原因不明。