The reason women who don't have babies do not see the nipple discharge on a regular occasion is because small pieces of breast tissue block the nipple ducts which keep the fluid within the breast instead of seeing lactation.

After becoming pregnant, the tissue is released to allow for lactation, in turn making it possible to breastfeed. Once breastfeeding has not been done for some time, tissue grows behind the nipple duct again, keeping nipple discharge from happening.

The most common reason for nipple discharge if not pregnant, is due to fondling or sucking of the breasts as well as irritation from clothing while being active. Drugs and hormone supplements are known to produce nipple discharge spontaneously and pituitary tumors can produce a milky nipple discharge.

This happens because a hormone that is produced by the pituitary gland is what triggers lactation in women when they are pregnant. If the pituitary gland is not normal in any way, it can effect lactation, therefore expressing nipple discharge when it is least expected.

A white or milky but non sticky nipple discharge would be seen in the previously mentioned scenarios. If a bloody or watery nipple discharge is experienced, it could mean that it is due to an infection.

This type of discharge could also mean you are dealing with a benign condition such as pilloma. Pilloma is a tumor that is not cancerous but is located inside the breast duct. Multiple pillomas could be present, in turn leaving you with an abnormal looking discharge.

Some nipple discharge could mean a cancerous tumor, but the discharge is almost always seen only on one breast. When nipple discharge is seen on both breasts, it almost always means a benign condition.

Although there are only a handful of reasons a woman would experience discharge, it is important to keep these in mind when trying to determine the cause of the lactation. Not only do hormone imbalances and pituitary issues cause this but sedatives, tranquilizers, and even birth control pills can affect nipple discharge.

It is important to seek medical advice when determining why lactation is present unexpectedly, as it would be almost impossible to determine this reason on your own!