Health disparities (differences in health by socioeconomic groups) are a pressing issue in our society. This article provides an overview of a multilevel approach that seeks to understand the mechanisms underlying health disparities by considering factors at the individual, family, and neighborhood levels. In addition, we describe an approach to connecting these factors to various levels of biological processes (systemic inflammation, cellular processes, and genomic pathways) that drive disease pathophysiology. In the second half of the article, ...