Nipple discharge is a normal part of breast function during pregnancy or breast-feeding. It also may be associated with menstrual hormone changes and fibrocystic changes. The milky discharge after breast-feeding will normally affect both breasts and can continue for up to two or three years after stopping nursing.

A papilloma is a noncancerous (benign) tumor that can be associated with bloody discharge. It appears spontaneously and involves a single duct. Although the bloody discharge may resolve on its own, this situation requires evaluation with an ultrasound of the area behind the nipple and areola. If the ultrasound shows a lesion within a milk duct, you may need a biopsy to confirm that it's a papilloma or to exclude a cancer.

Often, nipple discharge stems from a benign condition. However, breast cancer is a possibility, especially if:

  • You have a lump in your breast
  • Only one breast is affected
  • The discharge contains blood
  • The discharge is spontaneous and persistent
  • The discharge affects only a single duct

Possible causes of nipple discharge include:

  1. Abscess
  2. Birth control pills
  3. Breast cancer
  4. Ductal carcinoma in situ (DCIS)
  5. Endocrine disorders
  6. Excessive breast stimulation
  7. Fibrocystic breasts (lumpy or rope-like breast tissue)
  8. Galactorrhea
  9. Injury or trauma to the breast
  10. Intraductal papilloma (a benign, wartlike growth in a milk duct)
  11. Mammary duct ectasia
  12. Mastitis (an infection in breast tissue that most commonly affects women who are breast-feeding)
  13. Medication use
  14. Menstrual cycle hormone changes
  15. Paget's disease of the breast
  16. Periductal mastitis
  17. Pregnancy and breast-feeding
  18. Prolactinoma

Causes shown here are commonly associated with this symptom. Work with your doctor or other health care professional for an accurate diagnosis.

Jan. 11, 2018