COPD: Chronic Obstructive Pulmonary Disease

COPD is a group of common chronic respiratory disorders that are characterized by progressive tissue degeneration and obstruction in the airways of the lungs. They are debilitating conditions that affect the individual’s ability to work and function independently. Examples of these disorders are emphysema, chronic bronchitis, and chronic asthma .

Emphysema is destruction of alveolar walls leading to large, abnormal air spaces in the lungs. As in chronic bronchitis, cigarette smoking is its major cause. Deficiency of alpha-1-antitrypsin, an enzyme that normally prevents lung tissue destruction, also causes emphysema. When alveolar walls are destroyed, air spaces enlarge and the surface area for gas exchange decreases. The alveoli become less elastic and airways tend to collapse during exhalation. This causes air trapping in the lungs.

The onset of emphysema is insidious. Dyspnea occurs first on exertion and the progress until it is marked even at rest. Hyperventilation with a prolonged expiratory phage, use of accessory muscles, and hyperinflation leading to development of a “barrel chest” mark the ventilation difficulty. Typical posture is a sitting position, leading forward, to facilitate breathing. Hyperventilation maintains adequate oxygen levels until late stages. Anorexia and fatigue contribute to weight loss.

With this disease, and no treatment, severe consqences such as death can occur.