Breast cancer is a prevalent malignancy in women. Its incidence varies significantly around the world, with the United States and Northern Europe being the most prevalent regions, followed by Eastern and Southern Europe and South America, and Asia having the lowest incidence. Although the etiology of breast cancer is complex and the pathogenesis is not really understood, some etiological studies have shown that some relevant factors are associated with the development of breast cancer. (1) There is a correlation between family history and breast cancer. As early as 1974, Anderson et al. noted that women with a first-degree relative with breast cancer were 2-3 times more likely to develop breast cancer than those without a family history. The relative risk was up to 9 times higher if the first-degree relative had bilateral breast cancer before menopause. A survey conducted in Shanghai in 1988-1989 showed that the relative risk of breast cancer in women with a family history of breast cancer was 4.5, which shows that family history is an important risk factor. (2) Reproductive factors: Since breast cells undergo physiological proliferation due to the cyclical changes of hormone levels in the body and the increase of hormone levels in the body during pregnancy, the occurrence of breast cancer is related to the age of menarche, age of menopause, menstrual cycle, number of births, history of breastfeeding and marital status. The risk of breast cancer is higher in unmarried women, early menarche, late menopause, short menstrual cycle, less frequent menstruation and not breastfeeding. On the contrary, the risk is lower. (3) Sex hormone level is also one of the causes of breast cancer. Studies have shown that breast cancer is very rare in women younger than 20 years old and is not common in women younger than 30 years old. The incidence of breast cancer increases every year from the age of 35 and this increase in incidence continues almost throughout a woman’s life. Between the ages of 45 and 50, the increase tapers off slightly and then rises steeply again. The intake of exogenous estrogen will greatly increase the incidence of breast cancer, such as: oral estrogen-containing drugs, transdermal absorption of estrogen in volumizing lotions, and oral contraceptives. (4) Nutritious diet, fatty and high-calorie diet, and alcohol consumption all increase the risk of breast cancer. (5) Previous history of benign breast tumors. Other factors include radiation, viruses, chemical stimuli and certain diseases such as diabetes can also cause an increased incidence of breast cancer. In order to minimize the threat of breast cancer to women’s health, the first step is to prevent the cause of the disease, mainly by targeting the above mentioned causes and enhancing the body’s resistance to the disease. Certain risk factors for breast cancer are unavoidable. The risk of breast cancer can be reduced by dietary adjustments such as reducing excessive caloric intake, lowering fat intake, reducing excessive intake of meat, fried eggs, butter, sweets, etc., increasing the intake of green vegetables, fruits and carotenoids in moderation, and avoiding exposure to ionizing radiation. Recommendations: (1) Monthly breast self-examination for women older than 18 years of age. (2) Women aged 18-40 years should be examined by a physician once every three years. (3) For women older than 40 years old, annual examination by a physician. (4) Women between 30 and 35 years of age should have a mammogram as a basis for future comparison. (5) For women younger than 50 years old, consult your doctor for a mammogram depending on your individual situation. If you have a family history or personal history of breast cancer, consult your doctor about the frequency of mammograms. (6) For women older than 50 years old, mammography should be performed once a year.