It is defined as the absence of menses for three months in a woman with previously normal menstruation or nine months for women with a history of oligomenorrhoea. Disease statistics 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.
Treatments vary based on the underlying condition. Key issues are problems of surgical correction if appropriate and oestrogen therapy if oestrogen levels are low. For those who do not plan to have biological children, treatment may be unnecessary if the underlying cause of the amenorrhoea is not threatening to their health. However, in the case of athletic amenorrhoea, deficiencies in estrogen and leptin often simultaneously result in bone loss, potentially leading to osteoporosis.
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).