1.The color and shape of nipple overflow Milk-like fluid (less fat), sexual fluid plasma fluid, bloody fluid or plasma blood fluid, light green overflow. 2.What are the possible causes of nipple discharge? Ductal dilation of the breast, also known as “plasma cell mastitis, intraductal papilloma, cystic hyperplasia of the breast, amenorrhea-overflow syndrome, anterior pituitary hyperfunction syndrome, oral contraceptives, ductal ductitis, endocrine disorders, intraductal papilloma, cancer, hemophilia, purpura, superficial erosion of the nipple, breast fistula. 3.What tests are helpful for nipple overflow? Cytological smear of overflow, ultrasound, ductoscopy, mammogram, needle aspiration cytology of lumps, blood sampling for lactogen, brain CT or MRI, others. 4.What conditions require surgery? If the fluid is bloody, or if a mass is suspected by ultrasound or ductoscopy, then intraductal papilloma or intraductal papillary carcinoma is suspected and surgery can be considered.