Chronic obstructive pulmonary diseases

Abstract

Chronic obstructive pulmonary diseases (COPD) comprise several lung diseases which share the characteristics of obstruction of the airways and hypersecretion. The majority of patients have chronic bronchitis, chronic asthma and emphysema. Chronic bronchitis is an extremely common disease defined by the World Health Organization as “a persistent cough with excessive production of sputum for 3 or more months in the year for 3 successive years”. Typically, the patient is a middle-aged heavy smoker with recurrent respiratory infections. Emphysema and chronic bronchitis usually occur together because they have common etiological factors, i.e. cigarette smoking and air pollution. Emphysema is described as a condition of the lungs characterized by an increase in the volume of the air spaces distal to the terminal bronchioles with destruction of alveolar tissue. Asthma is defined as variable airway obstruction. The changes in severity of airway narrowing can occur spontaneously or as a result of therapy. Complete remission usually occurs between attacks. In some chronic asthma patients, the airway obstruction is not reversed by bronchodilatator agents.