The clinical manifestation is periodic bilateral breast swelling and pain, which can be accompanied by the formation of breast nodules, and the degree of pain and nodule size is related to the menstrual cycle. Secondly, acute mastitis occurs in lactating women, which is caused by acute purulent infection of breast tissue caused by bacteria infecting breast tissue through cracked nipples, and the clinical manifestation is swelling and pain of the affected breast with increased skin temperature. Thirdly, breast cancer may not have obvious clinical features in the early stage, but when the disease progresses to the advanced stage, there may be persistent pain in the breast, and hard and poorly mobile lumps may be palpated in the breast, and even the orange peel sign or dimple sign may appear.