ABSTRACT
Chronic obstructive pulmonary disease (COPD) has been defined by the Global Initiative for Chronic Obstructive Lung Disease as follows: COPD is a preventable and treatable disease with some significant extrapulmonary effects that may contribute to the severity in individual patients. COPD is the internationally preferred term, which includes chronic bronchitis, emphysema, chronic airflow obstruction and chronic airflow limitation, either alone or in combination. Some conditions that can cause airflow obstruction, such as cystic fibrosis and bronchiectasis, are not included in the term COPD. COPD has an insidious onset, usually occurs above the age of 50 years and is predominantly caused by smoking, although it does occur rarely in non-smokers. COPD is the term used internationally to refer collectively to several lung diseases that are progressive, irreversible and potentially life-threatening. COPD is characterised by airflow obstruction that does not change markedly over a period of several months.
