Breast tenderness is a common problem among women in daily life, and can be classified into three cases according to etiology: First, cystic hyperplasia, which is caused by uneven hyperplasia of the lobules of the breast before and after menstruation due to changes in the ratio of estrogen and progesterone, and breast tenderness is a normal physiological phenomenon that changes with the menstrual cycle. Second, acute mastitis, in breastfeeding women, if there is tenderness in the breast and a fluctuating lump is palpable in the breast, and the skin on the surface of the local breast is red and swollen and the pain is progressively increasing, you should go to a regular hospital for breast surgery and perform abscess incision and drainage in a timely manner. Thirdly, if breast cancer is large enough to invade the skin or surrounding nerves, and the lump is hard and painful to touch, ultrasound examination of the breast should be performed to clarify the diagnosis and decide whether to perform surgery after full evaluation by breast surgeons.