Amenorrhoea (BE), amenorrhea (AmE), or amenorrhœa, is the absence of a menstrual period in a woman of reproductive age. Physiological states of amenorrhoea are seen, most commonly, during pregnancy and lactation (breastfeeding), the latter also forming the basis of a form of contraception known as the lactational amenorrhoea method.
Clinicians should note vital signs and body composition and build, including height and weight, and should calculate body mass index (BMI). Secondary sexual characteristics are evaluated; breast and pubic hair development are staged using Tanner’s method. If axillary and pubic hair is present, adrenarche has occurred. With the patient seated, clinicians should check for breast secretion by applying pressure to all sections of the breast, beginning at the base and moving toward the nipple. Galactorrhea (breast milk secretion not temporally associated with childbirth) may be observed.
In preindustrial societies, menarche typically occurred later than in current industrial societies. After menarche, menstruation was suppressed during much of a woman's reproductive life by either pregnancy or nursing. Reductions in age of menarche and lower fertility rates mean that modern women menstruate far more often than they did under the conditions prevalent for most of human evolutionary history.