Why repeated asthma attack will cause emphysema

Bronchial asthma attack, due to bronchial smooth muscle spasm, mucosal edema, and increased secretion lead to the formation of the trachea complete obstruction, suction, inspiratory muscle contraction, thorax expansion, gas may still enter the alveolar; breath, closed tracheal depression , and further increased airway resistance, alveolar gas can not be fully discharged而使whole lung gradually expanded. But alveolar bronchial smooth muscle and elastic fibers no pathological damage, this can be alleviated if bronchial spasm, pulmonary gas can be discharged, sick child can be fully restored, therefore, emphysema is reversible. If long-term repeated attack, which would have led: ① bronchi and bronchioles between Waterloo proliferation of muscle hypertrophy, bronchiolo-forming organic stenosis; ② bronchial gland hyperplasia hypertrophy, viscous substances secreted large, thin bronchial obstruction; ③ thin bronchial wall cartilage damage, loss of normal stent, suction, bronchiectasis, gas may still enter the alveolar but breath, bronchial closure subsidence, gas can not be discharged within the alveolar gas accumulation and expansion; ④ long-term accumulation of gas, the pressure increased pulmonary alveolar bloated flexibility diminish, and finally break down, forming emphysema.