Athletic Amenorrhea Amenorrhea means the absence of menstruation.
Many factors account for the lack of menstrual cycles.
Missed periods are caused by pregnancy, birth control pills, and stress. Travel, menopause, drugs, and hormone imbalances can also stop periods. Women with eating disorders, such as anorexia nervosa, often do not have their periods. Athletic amenorrhea is caused by endurance training. As many as 20 percent of racing runners do not have periods.