Benign Nipple Discharge

Common Causes

Doctor and patient using digital tablet in clinic
Hero Images/Getty Images

Medications - Benign nipple discharge can be caused by birth control pills, or by other common medications, such as sedatives. This nipple discharge may be milky in appearance.

Infections - Sometimes an infection can cause nipple discharge. Your doctor may take a sample of the discharge fluid and send it to a lab for testing. If an infection is found, you may need to take antibiotics to clear it up.

Mastitis - If you are breastfeeding, and a milk duct becomes clogged, you may experience mastitis. Milk will collect behind a clogged duct, building up pressure and causing swelling. This can lead to infection as bacteria may grow in the trapped milk. Your breast may turn pink and might feel tender and lumpy. You might see pus discharge from your nipple. See your doctor if you think mastitis might be your problem.

Dense and Lumpy Breast Texture - If your breast tissue is dense and usually lumpy (cysts, fibroadenomas) you may see sticky brown or green nipple discharge.

Intraductal Papillomas - A tiny wart-like growth in breast tissue can sometimes puncture a duct. Don't be alarmed – these intraductal papillomas are common in premenopausal women and may occur in groups. Intraductal papillomas can be surgically removed if they become bothersome.

Pregnancy - During pregnancy, your breast tissue is maturing and preparing for breastfeeding. You may see clear or milky discharge (colostrum), which is normal.

Perimenopausal or Menopausal Nipple Discharge

Mammary Duct Ectasia - In some women who are nearing menopause, milk ducts may become swollen and clogged. These ducts are just beneath the nipple, and the swelling can cause your nipple to feel tender or irritated and may cause nipple discharge. Mammary duct ectasia can cause grey to green discharge that is thick and sticky. You can get relief from this condition by using warm packs, but if that doesn't help, see your doctor. If your ducts become infected, you may need to take antibiotics. In cases when the ducts will not return to normal size, they can be surgically removed, without causing a great change in the appearance of your breast.

Other Causes of Benign Nipple Discharge:

  • Thyroid malfunction can cause milky nipple discharge.
  • Scratchy clothing or bras that don't fit, continually rubbing or compressed your breast, may also cause nipple discharge.
  • A breast abscess, usually under your areola, can cause nipple discharge, signaling a bacterial infection.
View Article Sources
  • Source: National Cancer Institute. Understanding Breast Changes: A Health Guide for Women. PDF file. August 2004.