The patient’s breast feels hard, it may be a breast lump, a nodule of breast enlargement, or a lesion caused by milk stagnation, so it is recommended to go to the hospital for breast ultrasound examination for preliminary judgment, as follows: 1. Breast fibroadenoma: If the patient is relatively young, it is more likely to be a breast fibroadenoma. 2. Breast cancer: Usually, when ultrasound examination is done, it can be found that the boundary of the mass is not clear, there is internal calcification or abnormal blood flow signal, etc., and there may be metastasis in the axillary lymph nodes at the same time. 3. Breast hyperplasia: Usually, it is accompanied by periodic pain in the breast, and ultrasound examination can confirm the diagnosis. 4. Milk stagnation: Usually, it is found in some breastfeeding women. It is caused by blockage of the milk ducts or incomplete emptying of the breast.