Medical sociology is a subfield of sociology that focuses on the relationship between social factors and health, and the application of sociological theory and research techniques to questions related to health and the healthcare system. Medical sociologists study the social causes and consequences of health and illness, and are interested in the qualitative experiences of patients. They explore phenomena at the intersection of the social and clinical sciences, often working at the boundaries of public health, social work, demography, and gerontology. Some typical areas of research include the influence of ethnicity, gender, age, or socioeconomic status on the access to and quality of healthcare, health and risk-taking behaviors, social constructs of illness, health beliefs and perceptions, health effects of sociocultural changes, the role of health institutions and health professionals in society, and the social implications of biomedical innovations, education, and communication.

Medical sociology is usually taught as part of a wider sociology, clinical psychology, or health studies degree course, or on dedicated masters degree courses where it is sometimes combined with the study of medical ethics and bioethics. The field has a long history, but tended to be done as one of advocacy in response to social events rather than a field of study. Medical sociology is important because social factors play a critical role in determining or influencing the health of individuals, groups, and the larger society. Social conditions and situations not only promote and, in some cases, cause the possibility of illness and disability, but also enhance prospects of disease prevention and health maintenance. Medical sociologists now comprise one of the largest and most active groups doing sociological work in North America and Europe, and the field has expanded to other regions as well.