Breast cancer is one of the malignant tumors that seriously threaten women’s health, and its incidence rate is increasing year by year worldwide. According to statistics, China accounts for 12.2% and 9.6% of the number of new breast cancer cases and deaths worldwide. One out of every eight women in the United States will suffer from breast cancer. The high incidence of breast cancer has made many women talk about cancer. So who are the women who are prone to breast cancer? In fact, older women who are single, those who have no children, those who have their first child over 35 years old, those who have not given birth and are not breastfeeding, and those who have menstruation earlier than 12 years old or menopause later than 52 years old are more likely to develop this disease. The reason for the significantly higher incidence of the disease among women in large cities than in rural areas is also closely related to the stressful work life, unhealthy diet, lack of exercise, and lifestyle habits of urban women, which are closer to the Western model. Many people know that breast cancer is closely related to family genetic susceptibility to the disease, but what are the causes of the disease in those patients who do not have a family history of the disease? Studies show that in fact, only 10-15% of patients have a clear family history, and the majority of breast cancer patients probably have the cause from themselves. The incidence of breast cancer in China is trending younger and older unmarried women who have not had children are the target of breast cancer. During pregnancy or breastfeeding, progesterone and prolactin temporarily replace estrogen, reducing the over-stimulation of estrogen and leading to breast cancer. Studies have shown that women who do not have children, have repeated miscarriages or do not breastfeed after childbirth are closely associated with the occurrence of breast cancer. Therefore, age-appropriate childbirth and breastfeeding are currently advocated as a good way to prevent breast cancer. The reason for the high incidence of breast cancer in the United States is closely related to their long-term consumption of burgers and steaks. Please keep in mind that obese people have a higher incidence of breast cancer than thin people. For those women who like meat and seafood, they should realize that excess fat and protein in the body can interfere with estrogen levels, which are closely related to the development of breast cancer in women. Health supplements or breast enhancement products with high hormone content are also the cause of high estrogen, so large amounts or long-term consumption may also cause breast diseases and even breast cancer. Menopausal women often take some estrogen replacement drugs to relieve menopausal symptoms, not knowing that the presence of estrogen and progesterone in these drugs can increase the chance of breast cancer, so if you are taking these drugs, please pay attention to consult a mammographer and have regular checkups. Women who like to smoke, drink and stay up late also need to pay attention: drinking two glasses of wine a day will increase the chance of breast cancer by 21%; staying up late to work or play often will also increase the chance of breast cancer by 18%. After the age of 20, women should develop the habit of regular self-examination. The prime time for examination is 5-7 days after menstruation, because the hormone level in the body decreases at this time and the texture of the breast is the most relaxed, which is conducive to breast examination. Postmenopausal women or patients who have undergone hysterectomy can choose a fixed day of the month for self-examination. The examination can be done in the shower by applying bathing gel to the body and then touching the nipples in parallel with the fingers in the order of upper outer – lower outer – lower inner – upper inner, and finally squeezing them. When abnormal lumps or nipple overflow are found. You should go to the hospital promptly for examination. In self-examination, you should pay special attention to the upper outer area of the breast, where more than half of all breast cancers occur. It is important to note that self-examination cannot detect early breast cancer or carcinoma in situ, but annual medical examination is essential, and annual breast ultrasound is recommended before the age of 40, while mammogram and ultrasound screening are required for women after 40 to detect early breast cancer.