Yellow water flowing from the chest may be caused by papilloma, breast inflammation, breast cancer, breast hyperplasia and other reasons. 1. Papilloma: After the expansion of the milk ducts of the body, papilloma is easily produced, and after the rupture of the papilloma, it causes the yellow water to flow out, manifesting the yellow water in the chest. 2. Breast inflammation: Inflammation of the breast due to bacterial infection and other reasons, which leads to the phenomenon of yellow water outflow. 3. Ductal carcinoma in situ: the tumor that is prone to occur in breast is breast cancer, which often occurs in the epithelium of breast ducts. When the cancer spreads to the capillaries of breast ducts, the breast ducts will bleed, and after that, yellow or brown fluid will appear in the breast. 4. Breast hyperplasia: it is the most common lesion in female breast, which manifests as breast swelling or tingling and breast lumps, and a few patients may have nipple overflow, which is mostly clarified yellowish pulp. Should go to the hospital in time, symptomatic treatment, medication follow the doctor’s instructions.