[Concept of COPD, from past to the present].

The clinical concept of COPD initially started in conjunction with American Emphysema and British Bronchitis in CIBA Guest Symposium in 1958. JC Hogg, et al. recognized the peripheral airways as the major site of airflow obstruction in COPD in 1968. Thirty-six years later in 2004, JC Hogg, et al. described the pathological nature of small-airway obstruction in COPD. The GOLD project provided state-of-the-art information about COPD in 2001, in which it is stated that the chronic airflow limitation characteristic of COPD is caused by a mixture of small airway disease and parenchymal destruction. Cigarette smoke may accelerate the aging of lung or worsen aging-related events in lung by defective resolution of inflammation. Accelerated decline in lung function is recognized to occur in asthma, especially in those with asthma who smoke. With increasing age, there was a greater increase in the proportion of patients with overlapping COPD and asthma.