Neurasthenia and premenstrual syndrome became medical diseases because of the historical recognition of menstruation as a medical disease. Both the nineteenth and twentieth century cultural views of women were important in the establishment of menstruation, neurasthenia and premenstrual syndrome as medical conditions. Uncertainty of diagnosis with ever expanding diagnostic criteria, therapy undertaken without an adequate physiological basis, and often adverse effects from therapy, were characteristic of the medicalization of neurasthenia and premenstrual syndrome. A recognition of the cultural basis of these conditions is essential to a better understanding of women as human beings.