Chapter from the 2012 Youth Observatory Report: "Inequalities Among Young People Against the Backdrop of the Crisis," pp. 126–138. Social health inequalities result from a combination of socioeconomic and environmental factors, behaviors and lifestyles, and access to healthcare, in a cumulative process that begins even before birth and takes root during childhood and adolescence, with significant regional and gender disparities. While equitable access to care appears to be a major issue, the primary determinants of health inequalities lie outside the healthcare system. Young people in disadvantaged social circumstances generally exhibit significantly higher levels of substance abuse, sedentary behavior, and overweight. It is essential that public health measures do not exacerbate these inequalities.