COPD

COPD, short for chronic obstructive pulmonary disease, names a lasting, usually worsening lung disease in which airflow, especially breathing out, is persistently limited. It covers two overlapping processes that most patients have in varying degrees. In emphysema, the walls between the alveoli, the tiny air sacs, break down and lose their springiness, so air gets trapped in the lungs. In chronic bronchitis, the lining of the airways stays irritated and inflamed, swells and makes too much mucus.

The main cause is breathing in irritants for many years. Tobacco smoke accounts for most cases in wealthy countries, while smoke from cooking and heating with wood, dung or coal indoors is a major cause in poorer ones; workplace dust and fumes, poor lung growth early in life and a rare inherited lack of alpha-1 antitrypsin also play a part. Symptoms build slowly from middle age: a daily cough, often with phlegm, wheezing, tiredness and breathlessness that limits ordinary activity, with flare-ups called exacerbations that are often set off by chest infections. COPD is among the leading causes of death worldwide.

The diagnosis is confirmed by spirometry, a breathing test showing that air cannot be blown out fast enough. The damage cannot be undone, but stopping smoking slows the decline, and inhaled bronchodilators and steroids, vaccines, pulmonary rehabilitation and oxygen ease symptoms.