This paper develops the concept of epistemological alignment as a means of understanding how the medical emergency entered into biomedical classification. The working hypothesis is that the medical emergency could not develop as a paradigm from which knowledge could proliferate until a series of related concepts has been elucidates, and its epistemology became aligned. This argument is advanced by exploring the historically constructed lexicon of the medical emergency's key components. In the process, a semantic network created by 18th-century attempts to problematize sudden death is elucidates and explored. The paper concludes by arguing that the First World War served as a catalyst for the alignment of concepts central to the epistemology of the medical emergency.