Definition

Nipple discharge refers to any fluid that seeps out of the nipple of the breast.

Nipple discharge during pregnancy and breast-feeding is normal. Nipple discharge happens less commonly in women who aren't pregnant or breast-feeding. It may not be cause for concern, but it's wise to have it evaluated by a doctor to be sure. Men who experience nipple discharge under any circumstances should be evaluated.

One or both breasts may produce a nipple discharge, either spontaneously or when you squeeze your nipples or breasts. Nipple discharge may look milky, clear, yellow, green, brown or bloody. Discharge that isn't milk comes out of your nipple through the same ducts that carry milk. The discharge can involve a single duct or multiple ducts. The consistency of nipple discharge can vary — it may be thick and sticky or thin and watery.

Causes

Nipple discharge is a normal 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 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. 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 (lumpy or rope-like breast tissue)
  9. Galactorrhea
  10. Injury or trauma to the breast
  11. Intraductal papilloma (a benign, wartlike 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

Amenorrhea

Although the absence of menstruation (amenorrhea) is seldom serious, the condition can often be linked to an underlying problem requiring treatment.

Breast cancer

Ductal carcinoma in situ (DCIS)

Fibrocystic breasts

Galactorrhea

Male breast cancer

Mammary duct ectasia

Paget's disease of the breast