Tests to confirm/rule out galactorrhoea include an analysis of fluid from the nipple to see whether any blood is present; a blood test to check for the amount of prolactin in your system. If your prolactin level is high, your doctor might check your thyroid-stimulating hormone (TSH) level. She/he may order a pregnancy test, to exclude, or confirm, pregnancy as a possible cause of the nipple discharge.
Attribution: Avallain