When you are not breastfeeding, fluid leaking from one or both nipples is called nipple discharge. It may or may not be a sign of a medical problem.
Two types of nipple discharge are:
- Nonspontaneous discharge.
This occurs only when you press on your nipple. It is usually normal and occurs in the majority of women at one time or another. The discharge can be clear, cloudy, white, yellow, green, or brown. The more the nipple is pressed or stimulated, the more fluid is discharged. This type of nipple discharge does not usually mean that there is a problem.
- Spontaneous discharge.
This type of discharge occurs without pressing or stimulating the nipple. Fluid or blood from a nipple is a concern, except during pregnancy and breastfeeding. Galactorrhea is one type of spontaneous nipple discharge. It may be a side effect of a medicine or caused by a noncancerous tumor in the pituitary gland (pituitary adenoma), decreased thyroid function (hypothyroidism), or certain types of cancer.
Call your doctor if you have spontaneous nipple discharge, a discharge from only one nipple (unilateral), or one that looks like blood.