NIH research opportunities for the prevention and treatment for chronic conditions.

Chronic conditions constitute the leading cause of death and disability in the USA and constitute 86 per cent of the nation's annual healthcare expenses. Approximately half of all American adults have at least one chronic condition; 25 per cent of these Americans have two or more chronic conditions. The National Institutes of Health have funded many projects that explain epidemiology, risk factors, and prevention and treatment of chronic conditions, though research questions remain. This commentary discusses some past projects, current areas of interest, and funding opportunities from many NIH Institutes, Centers, and Offices.