The cause of breast cancer is not well understood. Although the cause of breast cancer is not clear, there are many causative factors. Generally speaking, breast cancer is the target organ of many endocrine hormones, such as estrogen, progesterone and lactogen, among which estrone and estradiol are directly related to the development of breast cancer. The incidence of breast cancer is higher between the ages of 45 and 50 and will continue to increase after menopause, which may be related to the increase in estrone levels in older patients. There may be a direct correlation between the early age of menarche and the late age of menopause. First-degree relatives with a history of breast cancer have 2-3 times the risk of developing the disease than the general population. Overnutrition, obesity, and fatty diets can enhance or prolong estrogen stimulation of breast epithelial cells, thereby increasing the risk of development. Environmental factors as well as lifestyle have a role in the development of breast. The onset of breast cancer is not clear though, and avoiding as many predisposing factors as possible can reduce the occurrence of breast cancer. If there is a nodule in the breast, you should go to the hospital for treatment or physical examination or examination in time. If the nodule is found to be not so good, puncture or surgery should be performed in time, and the result of early treatment of breast cancer is still more satisfactory.