Breast hyperplasia is only due to female endocrine disorder, that is, estrogen increases and progesterone decreases, which leads to breast structural disorder. Endocrine disorder is the main cause of mammary gland hyperplasia. The causes of mammary gland hyperplasia are as follows:

First, the symptoms of breast are synchronized with the changes of breast tissue. In other words, it changes with the menstrual cycle, that is, it repeatedly proliferates and rejuvenates with the periodic changes of estrogen and progesterone in the body. The main histopathological changes of mammary gland hyperplasia are excessive hyperplasia and incomplete recovery of mammary essence, which is the result of imbalance between estrogen and progesterone.

Second, from the age of onset, most patients are in a period of vigorous secretion of sex hormones, which is rare in adolescence and declines after menopause, which is consistent with the rise and fall of ovarian function.

Third, from the irregular manifestations of breast lesions, it also shows that it is caused by endocrine influence. Clinically, most patients with breast hyperplasia occur on the non-breast-feeding side, or the symptoms on the non-breast-feeding side are biased. However, the symptoms of mammary gland hyperplasia in unmarried patients can be relieved or cured by themselves after pregnancy, childbirth and breastfeeding.