Chronic obstructive pulmonary disease is a disease state characterised by airflow obstruction that is not fully reversible. It is predominantly caused by smoking, although other factors such as occupational exposures also contribute to the development. The obstruction arises from chronic inflammation in the airways and lung parenchyma. Chronic obstructive pulmonary disease produces symptoms, disability and impaired quality of life but significant airflow obstruction may be present before the patient is aware of symptoms. Chronic obstructive pulmonary disease is the preferred term for patients who may have been labelled as having chronic bronchitis or emphysema in the past. Chronic obstructive pulmonary disease is generally a progressive disease. If the patient stops smoking, the disease may still progress due to the decline in lung function that occurs with the normal aging process. However, ongoing smoking accelerates the process.
