amenorrhoea

an absence of MENSTRUATION , which is normal before puberty, during PREGNANCY and white breast-feeding is being carried out, and following the MENOPAUSE . Primary amenorrhoea describes the situation where the menstrual periods do not begin at puberty. This occurs if there is a chromosome abnormality (such as TURNER'S SYNDROME ) or if some reproductive organs are absent. It can also occur where there is a failure or imbalance in the secretion of hormones. In secondary amenorrhoea, the menstrual periods stop when they would normally be expected to be present. There are a variety of causes, including hormone deficiency, disorders of the HYPOTHALAMUS , psychological and environmental stresses, during starvation, ANOREXIA nervosa or depression.