Breast diseases, such as acute mastitis, cystic hyperplasia of the breast or breast cancer, can be related to bacterial infection, imbalance of the ratio of estrogen to progesterone or stimulation by estrone and estradiol hormones, as analyzed below: 1. Acute mastitis: most common in postpartum breastfeeding women, especially primiparous women, often in the first 3 to 4 weeks after delivery, due to nipple rupture or ulceration, bacterial invasion along the lymphatic ducts leading to breast infection. 2. Breast cystic hyperplasia: also known as mastopathy, is caused by the imbalance of the ratio of estrogen and progesterone, resulting in breast parenchyma hyperplasia as well as incomplete recuperation, partially located in the breast parenchyma of female hormone receptor quality or quantity of abnormalities, can also make the degree of breast hyperplasia is not uniform, resulting in this disease. 3. Breast cancer: Since the mammary gland is the target organ of many endocrine hormones, it is believed that estrone and estradiol are directly related to the development of breast cancer, and other etiological factors include early age of menarche, late age of menopause, hereditary factors, obesity, and fatty diet. When breast disease occurs, it is necessary to consult a doctor in time to make a clear diagnosis and then carry out targeted treatment.