Hard lumps six days after weaning can be caused by lactation, mastitis and breast enlargement. 1. Breast milk secretion not emptied: Although a woman has been weaned, breast milk will still be secreted on its own. The milk is not emptied effectively, leading to milk deposition and eventually forming hard lumps and swelling. 2. Mastitis: For women who have been weaned, prolonged milk stagnation will aggravate the symptoms of mastitis, and hard lumps may appear in the breasts six days after weaning. 3. Breast enlargement: Breast enlargement compresses the milk ducts, leading to narrowing or blockage of the milk ducts, and the milk is not completely absorbed to form the milk, which will result in a hard lump in the breast six days after weaning. In addition, tumors, breast trauma may also appear similar clinical manifestations, it is recommended that women after weaning should pay attention to breast maintenance, learn simple breast massage methods, and often self-check. If accompanied by abnormalities, go to the hospital in a timely manner, detailed examination of the cause of the disease, the right medicine.