Nipple discharge refers to any fluid that seeps out of the nipple of the breast.
Nipple discharge in women who are not pregnant or breast-feeding may not be abnormal, but it's wise to have any unexpected nipple discharge evaluated by a doctor. Nipple discharge in men 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 nipple 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.