When does a young girl's behaviour become a disease? In sixteenth-century Europe, the disease of virgins, or green sickness, was seen as a common disorder affecting young unmarried girls. Its symptoms included weakness, dietary disturbance, lack of menstruation and most significantly, a change in skin colour. Understanding of the condition turned puberty and virginity into medical problems, and proposed to cure them by bloodletting, diet, exercise, and marriage. Helen King examines the origins and history of the disease, from its roots in the classical tradition to its extraordinary survival into the 1920s, despite changes in how the mechanisms of puberty and menstruation were understood, and enormous shifts in medical theories and technologies. From menstrual disturbance to eating disorders, from liver disease to blood disorder, the disease of virgins has been adjusted throughout its history to fit medical fashions. However, little changed in the underlying ideas about the female body, and the need to regulate the sexuality of young women. This compelling study poses a number of questions about the nature of disease itself and the relationship between illness, body image and what we should call 'normal' behaviour.