Breast cancer epidemiological surveys have found that women with the following factors have a higher risk of developing breast cancer than normal women: ① early menarche (earlier than 13 years old) or late menopause (older than 55 years old), long menstrual period (more than 35 years); ② older age at first birth (older than 35 years old) or unmarried and infertile; ③ those who have never breast-fed; ④ those who have a mother or sister with breast cancer in their family; ⑤ those who have one side of the breast; ⑥ those who have repeated breast x-rays as teenagers or young adults; ⑧ those who have cystic hyperplasia of the breast; ⑨ those who are over-nourished and have had breast cancer. (⑤) Breast cancer on one side; (⑥) Thyroid cancer or cervical cancer; (⑦) Repeated chest X-ray in adolescence and young adulthood; (⑧) Cystic hyperplasia of the breast; (⑨) Excessive nutrition and obesity in middle age; (⑩) Long-term use of female hormones.