Observations on the pathogenesis of chronic airflow obstruction in smokers: implications for the detection of "early" lung disease.

Observations on the pathogenesis of chronic airflow obstruction in smokers: implications for the detection of "early" lung disease Cigarette smoking causes various pathological changes in the lungs, some of which may lead to chronic airflow obstruction, which is an important cause of respiratory morbidity and mortality. The changes attributable to smoking include large airway effects (mucous gland enlargement and mucous hypersecretion, smooth muscle hypertrophy, atrophy of bronchial walls); small airway changes (bronchiolar inflammation, fibrosis, ulceration, and tortuousity, with diffuse narrowing of the airways); and pulmonary emphysema."5 The relative roles of these patholo- gical features in causing chronic airflow obstruction have been examined and two hypotheses for its pathogenesis in smokers have been proposed.