This article describes how today in the United States neurologists diagnose forms of dementia, such as Alzheimer's disease and frontotemporal dementia. Taking as a starting‐point the pervasive context of uncertainty in the diagnosis of neurodegenerative diseases, it examines how uncertainty is not merely an epistemological obstacle to the making of knowledge. On the contrary, the article analyses how uncertainty positively incites the use of clinicians’ ‘feelings’ in diagnostic work. Drawing on observations of clinical consultations and team meetings, it studies how, alongside contemporary instruments of objectification, clinicians use, share, and discuss their ‘feelings’ to ultimately renew knowledge about brain diseases. In documenting the manner in which medical expertise is bound to a concrete experience of the world, this article further explores how experts’ ‘intuition’ can be grasped as a conscious and effortful process, rather than as something ineffable, resisting analysis, and confined to an unconscious background.