The purpose of this chapter is to explore how Julia Kristeva's approach to embodiment and boundary work extends understandings of how vulnerability, disgust, horror and uncertainty shape healthcare practices. Kristeva's oeuvre is based in Lacanian psychoanalytic theories and concepts as well as approaches from social and literary studies. In the case of this chapter, the focus is on her theorisation of the psychological defence mechanism of abjection — a response to the abject, where identity, order or system are thrown into disarray. The abject, which is our focus here, is the abject body, but the abject can also be social situations and activities that are polluting, betrayals of what is considered "right', and social positions that are considered defiled, stigmatised or associated with what destabilises our sense of certainty. Such an analysis affords the possibility of voicing both the significance and incomprehensibility of bodies that leak, the chaos of illness and disease, and their sometime monstrosity. An analysis of abjection situates much that is deemed "out of place' in healthcare. As this is the case, I draw on instances of health-related practices to show the relevance of the emotional defence of abjection to explanations about lack of boundaries, sullying of subjectivities and what is in operation when various attempts to regain boundedness and certainty are mobilised.