Men in the United States suffer more severe conditions, have consistently higher death rates, and die nearly 7 years younger than women. Health-related beliefs and behaviors contribute significantly to these gender differences. To explain why women and men adopt the health beliefs and behaviors that they do, this article reviews research examining gender differences in social experiences, cultural representations of gender, and additional social and institutional structures, such as the media and the health care system. This review reveals that North Americans collectively work diligently to reinforce stereotypically feminine or masculine behavior in themselves and others, and that the beliefs and behaviors fostered in men and boys, the resources available to demonstrate masculinity, and the resources boys and men use to enact gender are largely unhealthy. It illuminates how cultural dictates, everyday interactions, and social and institutional structures help to sustain and reproduce men's risks, and how the health beliefs and behaviors that people adopt are means for demonstrating femininities and masculinities.