"To diagnose galactorrhoea, your doctor will take a medical history, perform a physical exam. She/he may try to express some of the fluid by gently squeezing or pressing the area around your nipple. Your doctor will check for breast lumps or other suspicious areas of thickened breast tissue.
If your doctor finds a breast lump or other suspicious breast tissue during your physical exam, she/he may order a radiology test, e. g mammography or ultrasound, to get images of your breast tissue and to evaluate the area behind the nipple. If your blood test reveals high prolactin levels, you may have magnetic resonance imaging (MRI) to check for a tumor or other abnormalities of your pituitary gland.".
Attribution: Avallain