Nipple discharge is when fluid leaks from the nipple. It is a common breast symptom. Nipple discharge can be physiological or pathological, and be associated with benign or malignant disease. Nipple discharge alone (without a lump or other nipple changes) is an uncommon symptom of breast cancer.
What are the features of nipple discharge?
Nipple discharge can be
- Spontaneous (fluid leaks from the nipple without any squeezing of the nipple) or on expression (fluid comes out of the nipple only when the nipple is squeezed)
- Unilateral (from one breast) or bilateral (from both breasts)
- Single duct (from one opening on the nipple) or multiple ducts (from more than one opening on the nipple)
- Blood-stained, clear, green, milky or yellow in colour
Can nipple discharge be normal?
Yes. Fluid can be obtained from the nipples of around 70% of normal women when special techniques, massage or devices (e.g. breast pumps) are used. This discharge of fluid from a normal breast is called 'physiological discharge'.
Physiological discharge is typically on expression (rather than spontaneous), comes from multiple ducts and yellow, milky or green in colour.
Physiological discharge requires no treatment. It is important to stop expressing or squeezing the nipple and breast, as this causes more fluid to be made. The discharge will usually stop when you stop expressing.
When is nipple discharge abnormal?
Spontaneous nipple discharge unrelated to pregnancy or breastfeeding is abnormal.
There are many causes of abnormal nipple discharge, including
- Duct ectasia: a benign condition in which there is enlargement & inflammation of the milk ducts under the nipple
- Duct papilloma: a growth within the milk duct near the nipple
- Nipple eczema: dermatitis (or eczema) affecting the skin of the nipple
- Paget's disease of the nipple: a type of breast cancer involving the nipple
- Breast cancer
Nipple discharge that is spontaneous, blood-stained, persistent and unrelated to pregnancy or breastfeeding requires clinical assessment by your doctor and imaging of the breasts with ultrasound and mammogram (and sometimes MRI). A sample of the discharge fluid may be sent for examination under the microscope to look for cancer cells.
Note: nipple discharge associated with other symptoms such as a lump, skin or nipple changes always requires investigation, even if the discharge is not spontaneous or blood-stained.
Will I need surgery?
Surgery for nipple discharge is required for
- Diagnosis of blood-stained nipple discharge even if imaging shows no abnormality (as changes behind the nipple can be difficult to see)
- Treatment of the underlying disease (e.g. papilloma, breast cancer)
- Treatment of annoying discharge caused by benign conditions (e.g. duct ectasia)