A hard lump inside the breast that is movable and not painful is mostly considered to be a breast nodule. A nodule that is movable and not accompanied by painful symptoms is mostly a benign nodule, which can be seen in mastocytosis, mammary fibroadenoma, etc., or in breastfeeding women, where a hard lump is formed due to the accumulation of milk. Treatment is based on the regulation of sex hormone balance and surgical removal of the lump, which needs to be determined according to the patient’s individual situation. I. Physiological phenomenon: Since the breast is in a state of continuous milk secretion during breastfeeding, if the milk is not completely emptied after the baby eats, it is easy to form lumps in the ducts of the breast. Daily breastfeeding after timely emptying of milk, for the formed lumps can be massaged, as well as the use of hot towels wet breast, to promote local blood circulation, so that the lumps dissipate. Second, pathological phenomena: 1, mastoproliferative disease: mostly due to the imbalance of the ratio of estrogen and progesterone, resulting in excessive hyperplasia of the breast parenchyma and the formation of nodules. It can only appear as a movable soft nodular lump during the non-physiological period, but when the physiological period there can be significant swelling and pain, and the symptoms are reduced after the physiological period. The treatment is based on oral prolotherapy, tamoxifen and other drugs, and if it is ineffective, it can be surgically removed. 2. Breast fibroadenoma: It is common in young women, due to estrogen stimulation of breast lobules fibroblasts form nodules. The surface of the nodule is smooth and easy to push, and the physiological period has no effect on the tumor. Treatment is mainly surgical excision, while reducing the daily intake of hormone-rich food and avoiding the indiscriminate use of hormone-based drugs.