In the branchoscopic observation or pathologic examination, the changes of the bronchi in asthmatics during asthma attack were bronchoconstriction, mucous hypersecretion and edema or cellular response of bronchial wall. Suffocation was the most common cause of death in severe asthma, The adrenal atrophy was the most prominent in intractable asthma. The extrusion mechanisms of chemical mediators from the tissue mast cells were divided into two types. In light microscopic observation, the one was degranulation, and the other was decrease in number of granules. In electron micrograph, degranulation fell under eruptocrine mechanism and decrease in number of granules fell under transmembranous permeation. Both of them were prominent in the cases during attack.
