Why some groups or individuals appear to be more or less susceptible to specific diseases or illnesses has been and continues to be an area of active inquiry and is the focus of this text. Attention to this question necessitates input from and understanding across multiple disciplines including, but not limited to, epidemiology, sociology, anthropology, history, medicine, and genetics. Our ability to investigate and to answer questions of disease susceptibility, causation, and prevention is clearly limited by the boundaries of our knowledge in each relevant discipline, as well as our ability to integrate our understandings across disciplines.This text proceeds from a biocultural approach to the examination of health and illness in specific groups in the United States. This approach requires an examination of cultural and historical factors that affect the distribution and the natural history of diseases, such as methods of food preparation, beliefs about the cause of illness, and the availability of various medications and substances. The first portion of the text establishes the foundations for this inquiry, with chapters focusing on research ethics, research study design, and an examination of basic constructs such as race, ethnicity, gender, sex, sexual orientation, health care utilization, and health care-seeking behavior.The second portion of this text focuses on health and illness in specific subgroups: African-Americans, Asians and Pacific Islanders, Latinos, Native Americans, women, and communities with varying sexual and gender orientations. This emphasis may appear to be in contradiction to one of the basic premises of the first portion of the text: that we must move away from the use of race as a marker in health research and utilize, instead, a biocultural approach, which relies more heavily on ethnicity as a construct. Similarly, our construction of both sex and gender as polarized concepts, often inextricably linked together, demands extension if we are to find alternative explanations for our questions.A biocultural approach requires that we attempt to integrate not only the biology, the "hard science," into our search for answers, but also the history, the culture, and the experience of each group. This is clearly not an easy task. How can one generalize across the many diverse subgroups that we now classify as "Asian and Pacific Islander?" How can we continue to disregard the broad spectrum of history and culture within what we now call "African-American" or "black American," which encompasses individuals of Caribbean, African, and Latin American heritage, to name but a few? This task is rendered all the more difficult