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. Outside of the reproductive years there is absence of menses during childhood and after menopause. History of present illness includes whether menses have ever occurred (to distinguish primary from secondary amenorrhea) and, if so, how old patients were at menarche, whether periods have ever been regular, and when the last normal menstrual period occurred. History should also include duration and flow of menses; presence or absence of cyclic breast tenderness and mood changes; and growth, development, and age at thelarche (development of breasts at puberty).
General examination focuses on evidence of virilization, including hirsutism, temporal balding, acne, voice deepening, increased muscle mass, clitoromegaly (clitoral enlargement), and defeminization (a decrease in previously normal secondary sexual characteristics, such as decreased breast size and vaginal atrophy). Hypertrichosis (excessive growth of hair on the extremities, head, and back), which is common in some families
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. The term is derived from Greek: a = negative, men = month, rhoia = flow. Derived adjectives are amenorrhoeal and amenorrhoeic. The opposite is the normal menstrual period (eumenorrhoea).