Aunt generally refers to menstruation, breast swelling and pain during menstruation may be caused by hormonal changes, breast hyperplasia, breast fibroma and other diseases. 1. Hormonal changes: Hormonal changes in the female body during menstruation may cause some stimulation to the breast tissue, resulting in the phenomenon of breast swelling and pain, after the end of menstruation, the hormones in the body return to normal, and most of the phenomenon of breast swelling and pain will disappear on its own. 2. Mammary hyperplasia: Mammary hyperplasia is a disease in which the normal development and degeneration of the mammary glands are out of order, and it is related to the imbalance of estrogen-progestin ratio and the elevation of prolactin, etc., and the patients will have cyclic chest pain, which leads to breast swelling and pain during the menstruation period. 3. Breast fibroma: breast fibroma is a benign disease, mainly caused by the increased sensitivity of breast tissue to estrogen, pregnancy, taking estrogen drugs can trigger this disease, patients may experience chest pain during menstruation. There are more reasons for breast swelling and pain during menstruation, and patients need to be actively examined and cooperate with doctors for treatment. They should also choose the right size of underwear according to their bust size and keep the blood circulation of the breast tissue smooth.