Fibrocystic breast changes. Fibrocystic refers to the presence or development of fibrous tissue and cysts. Fibrocystic changes in your breasts may cause lumps or thickenings in your breast tissue. They do not indicate, though, the presence of cancer. In addition to causing pain and itching, fibrocystic breast changes can, at times, cause secretion of clear, white, yellow, or green nipple discharge. Galactorrhea. It might sound scary. But galactorrhea simply describes a condition in which a woman s breast secretes milk or a milky nipple discharge even though she is not breastfeeding. Galactorrhea is not a disease and has many possible causes. Infection. Nipple discharge that contains pus may indicate an infection in your breast. This is also known as mastitis. Mastitis is usually seen in women who are breastfeeding. But it can develop in women who are not lactating. If you have an infection or abscess in your breast, you may also notice that your breast is sore, red, or warm to the touch. Intraductal papilloma. These are noncancerous growths in the ducts of the breast. They are the most common reason women experience abnormal nipple discharge. When they become inflamed, intraductal papillomas may result in nipple discharge that contains blood or is sticky in texture.