This article critically explores the invisible roots of health inequity by examining how social determinants shape healthcare access and health outcomes across populations. Drawing on recent evidence, the paper highlights that health inequities persist not due to random variation but as products of structural and social mechanisms, such as socioeconomic position, education, housing, and systemic discrimination. These determinants influence not only disease patterns but also differential access to quality care, creating avoidable and unjust differences in health outcomes. The analysis also discusses the implications for policy and practice, emphasizing that addressing these social determinants is essential for achieving equitable health.