Chronic obstructive pulmonary disease: epidemiology, pathogenesis, disease course, and prognosis.

Chronic obstructive pulmonary disease (COPD) is the fourth leading cause of death in the United States and is increasing in incidence. COPD is easily identified in its early stages by spirometry, yet it is still underdiagnosed, largely because this simple test is not being done in patients at risk for the development of COPD. The most important risk factor by far is cigarette smoking-smoking cessation or even a decrease in smoking can substantially reduce the risk for the development and/or rate of progression of COPD. Increased public awareness, early diagnosis and intervention, and secondary prevention by primary care providers may help reverse the trend of escalating prevalence, mortality, and premature morbidity associated with COPD.