Definitions in chronic obstructive pulmonary disease.

States of airflow obstruction are common disorders which span the spectrum from asthmatic-chronic bronchitis to emphysema. Asthmatic and chronic bronchitic states are at least potentially reversible by systematic, pharmacologically oriented therapy focusing on bronchodilators and corticosteroids. Both asthmatic bronchitis, particularly when it is not adequately treated, and emphysema result in the final common pathway of COPD. These are generally progressive states, unless smoking cessation can be achieved in early or mild stages of disease. The future focuses on the great challenge of early identification, classification, and intervention. Thus, all patients with cough, dyspnea, and wheeze should be carefully evaluated by health workers who understand the history, physical examination, and simple pulmonary function tests in the context of chest radiology. These clinical methods together can help define the disease states characterized by airflow obstruction. Often, a final definition of disease cannot be made until aggressive attempts at the treatment of the airflow obstruction and its attendant symptoms complex have been vigorously pursued by experienced clinicians.