Definition COPD is a preventable and treatable disease with some significant extrapulmonary effects that may contribute to the severity in individual patients Its pulmonary component is characterized by airflow limitation that is not fully reversible The airflow limitation is usually progressive and associated with an abnormal inflammatory response of the lung to noxious particles or gases MBBS project, Zhongshan HospitalMBBS project, Zhongshan Hospital Definition • COPD is a preventable and treatable disease with some significant extrapulmonary effects that may contribute to the severity in individual patients. • Its pulmonary component is characterized by airflow limitation that is not fully reversible. • The airflow limitation is usually progressive and associated with an abnormal inflammatory response of the lung to noxious particles or gases