Definition of nipple discharge
Nipple discharge refers to any fluid that seeps out of the nipple of the breast.
Nipple discharge in a woman who’s not pregnant or breast-feeding isn’t necessarily abnormal, but it should be evaluated by a doctor. Nipple discharge in a man under any circumstances could be a problem and needs further evaluation.
One or both breasts may produce a nipple discharge, either spontaneously or when you squeeze your nipples or breasts. A nipple discharge may look milky, or it may be clear, yellow, green, brown or bloody. Nonmilk discharge comes out of your breasts through the same nipple openings that carry milk. The consistency of nipple discharge can vary — it may be thick and sticky or thin and watery.
Causes of nipple discharge
Nipple discharge is a normal part of breast function during pregnancy or breast-feeding. It also may be associated with menstrual hormone changes. The milky discharge after breast-feeding can normally continue for up to two years after stopping nursing. Sometimes during pregnancy, the color of the nipple discharge may be bloody. The discharge should resolve on its own.
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, you may need a biopsy to confirm that it’s a papilloma.
Most 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
- The discharge affects only a single duct
Possible causes of nipple discharge include:
- Breast cancer
- Breast infection
- Ductal carcinoma in situ (DCIS)
- Excessive breast stimulation
- Fibrocystic breasts
- Hormone imbalance
- Injury or trauma to the breast
- Intraductal papilloma
- Mammary duct ectasia
- Medication use
- Menstrual cycle hormone changes
- Paget’s disease of the breast
- Pregnancy and breast-feeding
When to see a doctor
Nipple discharge is rarely a sign of breast cancer. But it might be a sign of an underlying condition that requires treatment.
If you’re still having menstrual periods and your nipple discharge doesn’t resolve on its own after your next menstrual cycle, make an appointment with your doctor to have it evaluated. However, if you’ve completed menopause and you’re experiencing a spontaneous nipple discharge that involves one breast and a single duct, see your doctor right away for further evaluation.
In the meantime, take care to avoid nipple stimulation — including frequent checks for discharge — because stimulation actually makes the discharge continue.