Watery breasts, also known as nipple discharge, are seen in the following cases: First, if the discharge is bloody, it can be caused by a papilloma in the milk duct, and the examination will also palpate a smooth-edged swelling under the areola with mild tenderness. Ultrasound and ductoscopy can make a clear diagnosis and surgery should be chosen to remove the lesion promptly. In addition, patients with malignant breast tumors may also present with bloody breast discharge, which is usually located in the outer upper quadrant of the breast gland and is not associated with significant pain. However, the investigation will show that the surface of the lesion is not smooth, the boundary is not clear, and the mobility is poor, so it is considered that the tumor is locally necrotic and should be treated by radical resection surgery in time. Secondly, patients with breast enlargement may also show nipple overflow, which is usually plasma or milky white.