In recent years, medical sociologists have increasingly paid attention to a variety of interactions between social and biological factors. These include how social stressors impact the functioning of physiological systems, how sociocultural contexts trigger genetic propensities or mitigate genetic defects, and how brains are attuned to social, cultural, and interactional factors. This paper focuses on how both sociocultural and biological forces influence what conditions are contextually appropriate responses or disorders. It also suggests that some of the most obdurate health problems result from mismatches between natural genes and current social circumstances rather than from genetic defects. Finally, it examines how social environments have profound impacts on how much harm disorders create. It shows how sociological insights can help establish valid criteria for illnesses and indicates the complexities involved in defining what genuine disorders are.