Many women produce a small amount of nipple discharge if they squeeze their nipples firmly (not advised). This is due to a small amount of fluid that is produced naturally within the milk ducts. Discharge colour can vary in colour from clear through to white, brown, bloodstained or green.

More copious nipple discharge, or the sudden onset of nipple discharge where this had not occurred before should always be investigated. The most common causes are inflammation of the milk ducts in the breast or a small harmless wart-like growth (often only just the size of a pinhead and termed a papilloma), within a milk duct.

This symptom can also be associated with breast cancer and it is particularly important that the breasts are assessed quickly, particularly if you are aware of any blood within the discharge.

Nipple discharge is usually investigated with a mammogram, an ultrasound and by analysis of a small drop of fluid under a microscope. Sometimes it is necessary to carry out a small operation to remove one or more of the breast ducts for analysis in order to be absolutely certain of the cause of the discharge. A very new development in this field is breast duct micro-endoscopy. In this procedure a small camera is passed down through the natural opening in the nipple and the inside of the milk ducts are visualised. This can sometimes establish diagnosis without resort to surgery. The Harley Street Breast Clinic is one of the only centres in the UK that are experienced in breast duct micro-endoscopy.