This issue of Medical Clinics of North America provides the latest essential updates on COPD. The following topics are covered: pathobiological mechanisms; genes and the disease (alpha-l-antitrypsin); the environment, phenotype, and comorbidity; the role and potential of imaging; pulmonary function and its importance; exercise in testing and therapy; patients' perception and quality of life; exacerbations, causes, prevention, and treatment; an integrated approach to the medical treatment; meducal pneumoplasty, surgical resection, or lung transplant; and smoking cessation and environmental hygiene.