This article examines the extent to which the refusals of British conscientious objectors (COs) to fight during the First World War were pathologised through the lens of physical and mental health, and the ways in which such a pathology impacted their treatment in penal establishments. It argues that the government compromised the physical as well as the mental health of absolutist COs. The article also analyses the effects of the state's pathologising efforts upon objectors, and the methods through which the physical bodies of COs were utilised against, or annexed by, the authorities. Drawing on Cabinet Minutes, Prison Commissioner Reports, and COs' personal letters and memoir materials, it suggests that the case of COs offers an interesting comparison with the complex ways in which the phenomenon of 'shell-shock' was beginning to be understood in both somatic and psychological terms.