What is early COPD and why is it important?

There is increasing interest in the origins of chronic obstructive pulmonary disease (COPD), as it is envisaged that preventive efforts and treatment can modify its clinical course. The concept of early COPD is not new, but it has recently regained interest, given new population data, recent cellular and molecular advances and insights from clinical trials. To date, many knowledge gaps in the nature of early COPD still exist, mainly because COPD has always been considered a disease of the elderly, and little attention has been paid to the pathological changes occurring in the lungs of individuals at risk before they develop clinically evident COPD. Future studies should focus on identifying early pathological manifestations of COPD in order to prevent its progression in susceptible individuals. In this review, we aim to summarise what is known on early COPD, from the epidemiological, cellular and clinical perspectives.