Social categories do not represent individual characteristics but are the result of social construction. Sex/gender, for example, is a social category because assumptions of difference between sexes/genders are constructed through social action. These assumptions involve a hierarchical understanding whereby certain groups are valued positively and others negatively. Social categories thus support unequal power relations and are the starting point for discrimination and disadvantage. This is highly relevant to health research as discrimination, for example, can limit health resources and create health inequities. Besides sex/gender, there are other social categories such as ethnic origin, socio-economic status, place of residence, occupation, education, religion, physical or mental disability, sexual orientation or age. This list is not exhaustive and can be supplemented by any socially constructed category that represents a position within social relations of domination, or is associated with discrimination. From an intersectional perspective, there is no hierarchy of these different social categories. The PROGRESS Plus framework provides an overview of relevant social categories.