Causes of breast pain include the following: First, inflammatory diseases of the breast, such as lactation mastitis, non-lactation plasma cell cell mastitis, inflammatory reaction accompanied by redness, swelling, heat, pain, localized distension of the skin, the clinical symptoms are more serious, need to go to the hospital in a timely manner. Second, the more common breast hyperplasia, due to abnormal hormone secretion levels on the breast tissue caused by the stimulation of the menstrual cycle, and the menstrual cycle, swelling and pain will be significantly relieved after the onset of menstruation. Third, occupational lesions of the breast, some breast occupation, breast cancer development to a certain extent will also cause pain. Other more special cases may be breast development during puberty, breast reaction after sexual intercourse, and similar pain in the breast during pregnancy and miscarriage.