Chronic obstructive pulmonary disease (COPD) is not only an established major cause of mortality and morbidity but is increasing in worldwide prevalence despite current medical interventions. The natural history of COPD is punctuated by periods of acute symptomatic, physiologic, and functional deterioration or exacerbations. These events are responsible for considerable additional morbidity and mortality and impact on patients' long-term health status. Despite advances in understanding disease mechanisms and in treatment, exacerbations continue to be the major cause of COPD-associated hospitalization, and provision for their management incurs considerable health care costs. Although pharmacologic therapies may improve clinical outcomes, these benefits must be optimized by prompt diagnosis and delivery. This will require improved understanding of this complex disease by physicians and patients alike.