Breast cancer is one of the most common malignant tumors in women, accounting for 7-10% of all malignant tumors in the body and second only to uterine cancer in women. (1) Family history of breast cancer, especially if mother or sister had breast cancer; (2) Early menarche (before 12 years old) or late menopause (after 52 years old); (3) No pregnancy over 40 years old or first full-term birth after 35 years old; (4) High risk factors for those who had breast cancer on one side; (5) Atypical breast hyperplasia is 3-4% higher than normal breast cancer; (6) High risk factors for those who had breast cancer on the other side; (7) High risk factors for those who had breast cancer on the other side; (8) High risk factors for those who had breast cancer on the other side; (9) High risk factors for those who had breast cancer on the other side; (10) High risk factors for those who had breast cancer on the other side. (5) Breast cancer incidence rate is 3-4 times higher in those with atypical hyperplasia than in the normal population; (6) Those who have had repeated X-ray or chest radiographs; (7) Those who have had functional uterine bleeding or adenocarcinoma of the uterine body; (8) Obese women, especially those with significant weight gain after menopause or those with diabetes mellitus. (2) Take off your shirt in front of a mirror and check if the appearance is different from the previous month; (3) Raise your arms above your head and then slowly lower them, noting whether the movement of both breasts is consistent and balanced, and whether there are any indentations and changes in the skin pattern of the breasts during the movement; ( (4) sitting position, one hand on the knee, relaxed; the other hand from the inside of that upper limb with the finger belly slowly glide touch, from the bottom up to the side of the chest wall under the armpit, both sides, noting whether there are lumps and unusual sensations; (5) sitting, standing or supine position, one hand on the back of the head, the other hand with the finger belly around the four quadrants of the breast, and finally to the central area, ending alternately (6) Finally, gently squeeze the nipple with your fingers to see if there is any discharge overflow. Good lifestyle habits should be adopted (1) Optimize the diet structure. High-fat diet can increase the incidence of breast cancer, so it is necessary to reduce the fat intake appropriately; green vegetarian dishes, soy products and foods rich in vitamin A are good for reducing the occurrence of breast cancer. (2) Strengthen exercise and lose weight moderately. Overweight and obesity have a significant impact on the occurrence of breast cancer, especially postmenopausal breast cancer. Proper and regular exercise can reduce the risk of breast cancer. (3) Reduce smoking and alcohol. Some studies have shown that women who smoke and drink heavily have a much higher incidence of breast cancer than women who do not smoke or drink alcohol. (4) Tune in to your emotions. Studies have shown that the incidence of breast cancer is related to mental factors, so keeping a happy mood and avoiding excessive mental tension and anxiety can reduce its incidence to a certain extent. (5) It is worth mentioning that breastfeeding is a protective factor for breast cancer, so we advocate breastfeeding for the sake of the child and the mother herself. Therefore, we advocate breastfeeding for the sake of the child and the mother herself. Women should develop good habits, do regular self-examination of their breasts and seek medical consultation in time when abnormalities are detected.