Medical technologies of various kinds play an increasingly important role in medical treatment, but may also increase health inequalities if they are primarily used by high‐status patients. While many have problematised inequalities in the material access to medical technologies, differences in use and perception are also salient for explaining the relationship between medical technologies and health inequalities. This article attempts to theorise these inequalities by bringing health inequality research into dialogue with social constructivist perspectives on user‐technology relations. Based on qualitative interview data from a case study of the technological self‐management of type 1 diabetes, I construct three clusters of technological practices and perceptions corresponding to three broad user types. These user types are then discussed in the context of patient empowerment and the promotion of the active, autonomous and self‐reflective ‘expert’ patient in European health care systems. To the extent that they materialise and enforce institutional expectations which only the most resourceful patients will be able to live up to, medical technologies may serve to entrench and legitimate social inequalities in health and medical care. Research therefore needs not only to consider how medical technologies are distributed, but also their design and appropriation by users.