This document discusses how social stress from factors like neighborhood conditions, discrimination, and adverse childhood experiences can impact health and aging through biological pathways. Chronic stress gets under the skin by affecting telomere length, inflammation levels, epigenetic aging, and other regulatory systems. Studies show that social stress is associated with shorter telomeres in both human and animal research. Addressing social stress requires efforts at the individual, community, and policy levels to reduce health disparities and promote healthy aging.