当女子进入青春期后,卵巢内会不断发生有规律性、周期性的变化。在卵巢性激素的影响下,子宫内膜每月会发生修复、增生、分泌、萎缩、坏死、脱落和出血,表现为阴道流血,这称做月经周期。发生月经周期变化是受大脑皮层、中枢神经系统、丘脑下部、脑垂体、卵巢所控制和影响。加之月经期间盆腔明显充血,全身及生殖器官局部抵抗力降低,往往容易引起种种月经病。常见的有以下几种: When women enter adolescence, the ovary will continue to occur regularly, cyclical changes. Under the influence of ovarian sex hormones, the endometrium will undergo repair, proliferation, secretion, atrophy, necrosis, shedding and bleeding every month, manifesting vaginal bleeding, which is called the menstrual cycle. The menstrual cycle changes are controlled and affected by the cerebral cortex, central nervous system, hypothalamus, pituitary, ovary. Coupled with significant hyperemia pelvic during menstruation, systemic and genital organs to reduce local resistance, often easily lead to a variety of menstrual disease. Common are the following: