Economic inequality is one of the defining challenges of our time, with profound consequences on health. Inequality and Health: A Quantitative Approach examines the connections between socioeconomic disparities and health outcomes across continents, combining general pathology with the physics of complex systems. Drawing on international data, the book traces the rise of chronic disease, the growing crisis of national health systems, and the impact of diet, pollution, and climate change on the most vulnerable populations. Comparing countries as different as Italy, the United States, and Brazil, the authors show how deeply social and economic conditions shape the health of citizens. Through a rigorous yet accessible quantitative analysis, they navigate a vast landscape of statistics, from life expectancy trends to healthcare spending, to reveal what the data tell us about the state of global health and what needs to change to make well-being accessible to all.