Menstruation formed the bedrock of medieval concepts about how the female body functioned. In medieval Europe, menstruation was seen as the end result of a whole bodily process of purification, one unique to the female body. Menstruation was also seen as a necessary prerequisite for conception. In fact, many references to menstruation in the context of fertility see the successful completion of its purgative function as key to fertility—a fact crucial to understanding why emmenagogues (preparations for bringing on menstruation) were not necessarily seen as abortifacients but may well have had a deliberately pronatal purpose. This essay examines various notions surrounding menstruation in medieval Europe, including why the menses were called "women's flower," in what circumstances they were likened to poisons, and why in some instances men were thought capable of "menstruating," too. Outside of medical contexts, menstruation is largely seen as nefas, something that cannot or should not be named or spoken about. Thus, medical discussions of menstruation are our main source for reconstructing beliefs and attitudes toward this key aspect of female physiology.
Monica H. Green (Sat,) studied this question.