Breast swelling and pain with hard lumps before menstruation may be caused by physiological hormonal fluctuations, or it may be due to pathological reasons such as cystic hyperplasia of the breast and acute mastitis. 1. Physiological: fluctuations in estrogen levels before menstruation will make the breast ducts expand, breast tissue edema, resulting in swelling and pain, this is a normal phenomenon, you can massage to relieve discomfort, in addition to pay more attention to rest. 2. Pathological: breast swelling and pain and hard lumps before menstruation, if the swelling and pain is reduced after menstruation, the hard lumps disappeared is likely to be cystic hyperplasia of the breast. Breast swelling and pain usually appear periodically before menstruation, and then relieved after menstruation, the hard lump in the breast is usually tough, and the boundary with the surrounding tissues is not clear. It is also possible that the hard lumps with swelling and pain in the breasts are not related to the menstrual cycle. Confined redness, swelling and hot pain in the breasts, accompanied by fever and chills, are usually acute mastitis. If the hard lump in the breast does not dissipate after menstruation and lasts for a long time, it may be a fibroid tumor or even breast cancer. In this case, it is recommended to go to a regular hospital for further examination by ultrasound and molybdenum target.