Amenorrhea is the absence of menstrual bleeding. Amenorrhea is a normal feature in :- prepubertal,
- pregnant,
- postmenopausal females.
In females of reproductive age, diagnosing amenorrhea is a matter of first determining whether pregnancy is the etiology. In the absence of pregnancy, the challenge is to determine the exact cause of absent menses. This article reviews the physiologic aspects of menstruation and presents an approach for ascertaining the etiology of amenorrhea. Only the main components of amenorrhea are highlighted. Many minor components of physiology are important but are beyond the scope of this article.
Pathophysiology
The menstrual cycle is an orderly progression of hormonal events in the female body that results in the release of an egg. Menstruation occurs when an egg released by the ovary remains unfertilized; subsequently, the soggy decidua of the endometrium (which was primed to receive a fertilized egg) is sloughed in a flow of menses in preparation for another cycle.