COPD remains a major cause of ill health, disability, healthcare costs and premature mortality. Scientists and clinicians across many countries have made great efforts to understand this important disease, and these have yielded positive results. This Monograph provides an up-to-date overview of what is happening in this exciting field, both at a basic and a clinical level. Beginning, crucially, with the patient s perspective, the chapters that follow consider the best way to define COPD, changes in the disease s incidence and prevalence, and offer new insights into the role of the microbiome in COPD, advances in imaging and treatment options, both pharmacological and non-pharmacological. Taken together, these chapters are an important contribution to the Monograph series and the COPD field in general.