This work assembles three historical medical treatises that survey major medieval epidemics — the plague, the dancing mania, and the sweating sickness — combining primary documents, contemporary accounts, and scholarly commentary. The author analyzes disease symptoms, modes of spread, and competing medical explanations while tracing social consequences such as mass panic, scapegoating, and institutional responses. Comparative readings highlight recurring patterns across outbreaks and the limits of period medicine. The volume includes translations, appendices with rare pamphlets, and an appeal for systematic collection of epidemic data to enable broader, evidence-based study of infectious phenomena.