The hardness of breast milk may be physiological, such as too much milk caused by localized stagnation, at this time the stagnation of milk can be emptied; there may be nipple inversion, milk cysts, mastitis and other pathological factors lead to the need for timely medical treatment of the original disease, the symptom will be relieved. 1. Physiological factors: excessive milk secretion, the baby can not finish sucking, localized stagnation caused by breast fullness, pain, this situation should be the stagnant milk out, hard lumps will disappear. 2. Pathological factors: (1) nipple inversion: nipple inversion affects breastfeeding, the baby is difficult to suck on the nipple, the milk is not easy to be sucked out, the hoarded milk leads to breast swelling with hard lumps, you can use breast pump, use negative pressure to attract the nipple to lift the nipple, and at the same time will be the accumulation of milk in the mammary glands of the milk to empty, it can improve the symptom of hard lumps of milk. (2) Accumulated milk cysts: the breast milk is not discharged well, resulting in the accumulation of milk in the breast to form a swelling. This condition can be relieved by hot compresses and massages, and at the same time emptying the breast milk, if necessary, puncture and pumping. (3) Mastitis: the affected side of the breast will be enlarged, localized hardness, and accompanied by increased skin temperature, skin redness, pressure pain, this situation can be treated with anti-inflammatory drugs; if an abscess is formed, it is necessary to make an incision and drainage, and the symptoms can only be relieved after the pus is discharged. If you are breastfeeding and have hard lumps in your breasts, if you exclude physiological factors, you should consult a doctor to find out the cause of the lumps and treat them.