COPD: causes and pathology

Chronic obstructive pulmonary disease (COPD) is a general term encompassing several previously used clinical labels such as ‘chronic bronchitis and emphysema’, 'chronic obstructive airways disease' and 'chronic obstructive lung disease'. COPD is defined by the Global Initiative for Obstructive Lung Disease (GOLD) as 'a disease state characterised by airflow limitation that is not fully reversible. The airflow limitation is usually both progressive and associated with an abnormal inflammatory response of the lungs to noxious particles or gases'. Few population-based prevalence surveys of COPD have been published. Data based on physician diagnosis from the UK General Practice Research Database indicate a prevalence in 1997 of 1.7% in men and 1.4% in women. The prevalence of COPD in men reached a plateau in the mid-1990s, but continues to increase in women. In the UK, about 30,000 deaths/year are caused by COPD; this accounts for about 6% of all male and 4% of all female deaths. The annual NHS workload for COPD exceeds that of asthma. About 25% of all medical admissions are as a result of respiratory diseases, and more than 50% of these are cases of COPD. In general practice, annual consultation rates for COPD increase with age from 417/10,000 population in 45—64-year-olds to 1032/10,000 population in 75—84-year-olds.