The ability to squeeze out clear water from one side of the breast usually indicates a ductal lesion, which may also be caused by breast enlargement or breast cancer. When a lesion occurs in the ducts of the breast, it usually manifests as fluid or blood spillage from the nipple, which can be red, light red, and clear, plasma, etc. A mass, usually about the size of a soybean or fava bean, can be palpated under the nipple and areola. Ultrasound of the breast and lactoscopy can be performed to clarify. If the lesion is considered to be a ductal lesion, the mass will usually need to be removed for pathological examination. If it is considered to be intraductal papilloma, regular review can be done by simple excision. If it is a papillary carcinoma, a segmental mastectomy and, if necessary, a total mastectomy are usually performed. Mammary gland hyperplasia may also lead to breast overflow, which is usually accompanied by periodic pain in the bilateral breast after the estrogen level rises in the premenstrual period. Ultrasound examination of the breast can be performed to rule out nodules and masses inside the breast. If the diagnosis is due to breast enlargement, you should take oral Chinese medicine for symptomatic treatment. Of course, breast cancer may also manifest as nipple overflow or clear water, so further ultrasound examination is needed to determine. If breast cancer is diagnosed as the cause of breast cancer, a modified radical breast cancer surgery is usually required.