Yellow water coming out of the breast is not a criterion to determine breast cancer, but it may be related to breast cancer, intraductal papilloma or mastitis. 1. Breast cancer: Breast cancer is malignant lesion, early clinical manifestation is painless lump in the breast, in the middle and late stage, there may be nipple discharge symptoms, the liquid may be yellow, or bloody liquid, some of them may be accompanied by nipple inversion, lymphatic enlargement, etc., but the diagnosis must be made by the corresponding pathology examination to confirm the diagnosis. 2. Intraductal papilloma: this disease is benign, after the onset of the disease may be manifested, the nipple extrusion of yellow fluid, some may appear yellow-brown, brown fluid, accompanied by lumps under the breast. 3. Mastitis: the cause of the disease is bacterial invasion of the breast, resulting in lesions, if there is an abscess, the pus may flow from the nipple area, manifested in the nipple extrusion of yellow water. If you have a nipple with yellow water, it is recommended that you consult a doctor in time, complete the relevant examination under the guidance of the doctor, and follow the doctor’s instructions to carry out symptomatic intervention.