Nipple discharge is a typical part of breast function during pregnancy or breast-feeding. It may also be associated with menstrual hormone changes and fibrocystic changes. The milky discharge after breast-feeding usually affects 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. The discharge associated with a papilloma often occurs spontaneously and involves a single duct. Although the bloody discharge may resolve on its own, your doctor will likely recommend a diagnostic mammogram and a breast ultrasound to see what's causing the discharge. You may also need a biopsy to confirm that it's a papilloma or to exclude a cancer. If the biopsy confirms a papilloma, your doctor will refer you to a surgeon to discuss treatment options.

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 or is clear
  • 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. Breast infection
  5. Ductal carcinoma in situ (DCIS)
  6. Endocrine disorders
  7. Excessive breast stimulation
  8. Fibrocystic breasts (which tend to feel lumpy or have a ropelike texture when checked by a health care provider.)
  9. Galactorrhea
  10. Injury or trauma to the breast
  11. Intraductal papilloma (a benign growth in a milk duct.)
  12. Mammary duct ectasia
  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.

Dec. 04, 2021