Chronic obstructive pulmonary disease COPD is a chronic inflammatory condition of the airways characterised by persistent airflow obstruction. In contrast to asthma where the airway inflammation leads to variable airflow obstruction, the airflow obstruction in patients with COPD is usually irreversible and progressive.
COPD is expected to become the third most common cause of morbidity and mortality worldwide by 2020. In the UK the prevalence of COPD has been estimated at around 2%, but this is most likely underestimated as many patients complaining of respiratory symptoms remain undiagnosed in primary care.
Aetiology and pathophysiology
Cigarette smoking is the most important risk factor for the development of COPD. In developing countries, the burning of indoor biomass cooking fuels is being recognised as a significant risk for the disease. Other factors include: passive smoking, genetics eg. alpha-1 anti-trypsin deficiency, environmental air pollution, occupational exposures eg. coal mine workers, childhood respiratory illness which predisposes to chronic adult disease, recurrent bronchopulmonary infections, and chronic asthma.Airway inflammation.Mucus gland hyperplasia.Airway fibrosis. Emphysema with alveolar wall destruction of the alveolar walls.