Amenorrhea is the absence of menstruation. Menstruation is a woman's monthly period.
Primary amenorrhea is when a girl has not yet started her monthly periods, and she:
Has gone through other normal changes that occur during puberty
Is older than 15
Primary amenorrhea; No periods - primary; Absent periods - primary; Absent menses - primary; Absence of periods - primary
Causes, incidence, and risk factors
Most girls begin menstruating between ages 9 and 18, with an average of around 12 years old. Primary amenorrhea typically occurs when a girl is older than 15, if she has gone through other normal changes that occur during puberty. Primary amenorrhea may occur with or without other signs of puberty.
Being born with poorly formed genital or pelvic organs can lead to primary amenorrhea. Some of these defects include:
If the condition is caused by a body-wide (systemic) disease, treatment of the disease may allow menstruation to begin.
If the amenorrhea is due to anorexia or too much exercise, periods will often begin when the weight returns to normal or the exercise level is decreased.
If the amenorrhea cannot be corrected, medicines can sometimes create a menstrual-like situation (pseudomenstruation). Medicines can help the woman feel more like her friends and family, and protect the bones from becoming too thin (osteoporosis).
The outlook depends on the cause of the amenorrhea and whether it can be corrected with treatment or lifestyle changes.
Periods are unlikely to start on their own if the amenorrhea was caused by one of the following conditions:
Styne DM, Grumbach MM. Puberty, ontogeny, neuroendocrinology, physiology, and disorders. In: Melmed S, Polonsky KS, Larsen PR, Kronenberg HM, eds. Williams Textbook of Endocrinology, 12th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 25.
Bulun SE. The physiology and pathology of the female reproductive axis. In: Melmed S, Polonsky KS, Larsen PR, Kronenberg HM, eds. Williams Textbook of Endocrinology, 12th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 17.
Linda J. Vorvick, MD, Medical Director and Director of Didactic Curriculum, MEDEX Northwest Division of Physician Assistant Studies, Department of Family Medicine, UW Medicine, School of Medicine, University of Washington; and Susan Storck, MD, FACOG, Chief, Eastside Department of Obstetrics and Gynecology, Group Health Cooperative of Puget Sound, Bellevue, Washington; Clinical Teaching Faculty, Department of Obstetrics and Gynecology, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M. Health Solutions, Ebix, Inc.