Solid breast nodules may be caused by breast fibroma, breast cancer, hyperplastic breast nodules, etc. 1. Breast fibroma: it is a benign breast tumor, which is a solid nodule formed due to the abnormal sensitivity of glandular epithelium or fibroblasts in a certain area of breast tissue to estrogen and overgrowth, and is characterized by a round or similar to a round lump, which has a smooth surface, clear boundaries, and can be moved. 2. Breast cancer: it is a malignant tumor of the breast, a solid nodule, the lump is hard and difficult to be pushed, the edge of the lump is uneven, the border is blurred and the shape is irregular. 3. Breast hyperplastic nodule: it is caused by the imbalance of female progesterone secretion, which causes the breast and the ducts of the breast to hyperplasia. If there are no uncomfortable symptoms, they can be left untreated for the time being, but need to be closely observed and regularly rechecked. Meanwhile, intraductal papilloma of the breast, sclerosing mastopathy, and breast tuberculosis may also manifest as solid nodules, which need to be carefully identified. If they manifest as solid breast nodules, early and standardized treatment is recommended to minimize the adverse effects of the disease.