Epidemiology of chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a disorder that is characterized by progressive reduction in forced expiratory airflow in excess of the normal age-related decline. Eventually, the reduction in airflow leads to exercise impairment, increased susceptibility to respiratory infections and irritants, and reduced life expectancy. Obstructive ventilatory defects occur in a number of lung disorders, including asthma, bronchiectasis, cystic fibrosis, immunoglobulin deficiency, lymphangioleiomyomatosis, and eosinophilic granuloma. In common practice, however, COPD is usually used to refer to the tobacco smoking-related diseases chronic bronchitis and emphysema.