OBSTRUCTIVE LUNG DISEASE



The obstructive lung diseases are characterized by reduction of expiratory flow rates and include asthma, emphysema, chronic bronchitis, bron­chiectasis- and cystic fibrosis. However, contro­versy and confusion reign over the definition of these individual disorders because of the marked overlap of clinical and pathophysiological fea­tures. Some have even suggested the abandon­ment of the traditional names and the substitution of groupings based on signs and symptoms. Chronic mucus hypersecretion, with or without obstruction, and chronic airways obstruction, re­versible or nonreversible, are probably more use­ful designations than debating whether a patient has chronic bronchitis or asthma. However, be­cause these are not in general use, we will try to define each of the diseases as currently under­stood, pointing out overlap when it exists