Mastitis – Benign Breast Infection

Mother breastfeeding her baby
Monashee Alonso/Caiaimage/Getty Images

What is Mastitis?:

Mastitis is a benign (non-cancerous) breast condition that can occur if you are breastfeeding. A milk duct may become clogged, and milk will collect behind it, building up pressure and causing swelling. This can lead to infection, as bacteria can grow in the trapped milk. Your breast may turn pink and might feel tender and lumpy. You might see pus discharge from your nipple.

What Does Mastitis Feel Like?:

You may not have all of these symptoms, but here are some that are common with mastitis:

  • pain during let-down (when milk is released into the milk ducts)
  • clogged area of the breast feels full and sore
  • pain around the area of the clogged duct
  • skin redness, possibly reddish/purplish areas
  • hard, lumpy area (engorgement)
  • fever
  • fatigue
  • flu-like symptoms

Cause of Mastitis:

Bacteria (Staphylococcus aureus) can enter your breast through an opening in the skin, such as a dry, cracked nipple. Once inside your breast tissue, the bacteria can cause an infection. When the infection becomes inflamed, pain, swelling, and redness result. If you develop mastitis and don't have it treated, it can develop into a pocket of pus, called an abscess.

Chronic Mastitis:

Women who aren't breastfeeding and may be postmenopausal can develop chronic mastitis. In this case, the milk ducts below your nipple become inflamed.

Your milk ducts can become clogged with dead skin cells and other debris.

Does Mastitis Show up on a Mammogram or Ultrasound?:

Mastitis shows up on a mammogram as bright white areas. If there is a doubt as to whether or not your mammogram is showing mastitis, an ultrasound exam can be ordered to confirm the diagnosis.

How is Mastitis Treated?:

Your doctor may prescribe antibiotics to clear up the infection. You can apply warm compresses to help expand the ducts and relieve the pain. It's also a good idea to keep nursing or expressing breast milk to empty the lobes and ducts of milk. This reduces pressure on your breast. Keep your nipples dry and clean between feedings, and drink plenty of water and fruit juice.


MedlinePlus. National Institutes of Health. Breast infection. Updated: 5/10/2006.

Continue Reading