Breast cancer is the malignant tumor with the highest incidence in women. The exact cause of breast cancer is still unclear, but it is generally believed that the occurrence of breast cancer is related to several factors. The relative risk of breast cancer increases 2.2 times when the age of menarche is less than 12 years old compared to more than 17 years old, and the risk of breast cancer doubles when the age of menopause is more than 55 years old compared to less than 45 years old. Genetic factors, some studies found that women whose mothers had bilateral breast cancer before menopause have 9 times higher risk of breast cancer than the average woman, and the average age of breast cancer in the second generation of breast cancer patients is about 10 years lower than the average person. Women who have a sister with breast cancer are three times more likely to develop breast cancer themselves. However, it is important to emphasize that breast cancer is not directly inherited from the disease. Childbirth has a protective effect on the breast, but only for those who had a full-term birth before the age of 30. Recent studies have concluded that breastfeeding also has a protective effect on the breast. 5. Unhealthy “high-calorie, high-fat” dietary habits result in a much higher incidence of breast cancer. The risk of breast cancer increases when children and adolescents have received breast radiotherapy. 7. Unhealthy lifestyle, some female white-collar workers who work in office for a long time sit more and move less and lack of exercise. 8. Mental depression and excessive tension, according to the survey, introversion, long-term mental depression and unhappy early life are important factors leading to cancer. 9. Young urban women face fierce competitive pressure and their spirits are in a state of stress for a long time, which easily leads to emotional instability. These mental factors together with bad life and work style will cause further damage to breasts. 10.Inappropriate use of estrogen-containing related drugs or products (including health products, cosmetics, etc.) 11.Environmental pollution, pesticide carcinogens, etc.