The epidemiology, etiology, clinical features, and natural history of emphysema.

The burden of disease attributable to emphysema is significant and growing, and is a leading cause of disability in middle and late life. There has traditionally been a rather nihilistic attitude toward emphysema and COPD, but with recent advances in the understanding of aetiological, pathophysiological, and prognostic mechanisms, and the increase in treatment options, this approach is no longer appropriate.