Any fluid that seeps out of the nipple of the breast is termed as Nipple discharge.
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. Non-milk 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.
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 it could also be a sign of breast cancer.
Possible other causes of nipple discharge include:
- Breast infection
- Excessive breast stimulation
- Fibrocystic breasts — lumpy or rope-like breast tissue
- Hormone imbalance
- Injury or trauma to the breast
- Mammary duct ectasia
- Medication use
- Menstrual cycle hormone changes
- Paget's disease of the breast