Rheumatic diseases affect a significant portion of the population and lead to increased health care costs, disability, and premature mortality; effective preventive measures for these diseases could lead to substantial improvements in public health. Natural history studies show that for most rheumatic diseases there is a period of preclinical disease development during which abnormal biomarkers or other processes can be detected. These changes are useful to understand mechanisms of disease pathogenesis; in addition, they may be applied to estimate a personal risk of future disease while individuals are still relatively asymptomatic and ultimately be used to identify individuals who may be targeted for preventive interventions.