Current Overview of COPD with Special Reference to Emphysema

Pulmonary emphysema is a chronic disease defined pathologically as an abnormal permanent destruction and enlargement of air spaces distal to the terminal bronchioles, accompanied by the destruction of alveolar walls without predominant fibrosis. Emphysema frequently occurs in overlapping association with chronic bronchitis which is clinically defined as chronic productive cough for three months in each of two successive years in a patient in whom other causes of chronic cough have been excluded. Previously, emphysema and chronic bronchitis was regarded as distinct entities and grouped under the umbrella term Chronic obstructive pulmonary disease(COPD).