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:

  1. You have a lump in your breast
  2. Only one breast is affected
  3. The discharge contains blood
  4. The discharge is spontaneous and persistent
  5. 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
  9. Galactorrhea
  10. Injury or trauma to the breast
  11. Intraductal papilloma
  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. 10, 2016