Based on fieldwork among Danes with a diagnosed risk of type 2 diabetes or cardiovascular disease, this paper investigates how the technological possibilities of diagnosing and monitoring invisible risks shape understandings of health and form subjectivity. It focuses on the experiences of being diagnosed with a risk condition in the form of high blood pressure or elevated blood glucose and the ensuing use of measuring devices. It argues that measurements of these conditions can be seen as 'formative processes' that produce and maintain a view of health as something that can best be known through the use of medical technology. The numerical values such measurements yield are seen as true indicators of health, and doing something about risk conditions is felt to be a personal imperative. The formative processes illustrated in this paper are motivational and thought provoking. The informants do not experience new symptoms after being diagnosed; rather they reflect upon their health in a new way and numbers become associated with personal responsibility and morality. However, because numbers influence subjective experiences, they can come to take up too much space in everyday life. Therefore, people have reservations about how often they should measure their values at home. The formative processes of being diagnosed with a risk condition are thus about subjectivity both in the sense of being subject to the demands of living with an illness and of being a subject who acts to keep life from being colonized by concerns about health.
