Overview

Mastitis is an infection of the breast tissue that results in breast pain, swelling, warmth and redness. You also might have fever and chills. Mastitis most commonly affects women who are breast-feeding (lactation mastitis), although sometimes this condition can occur in women who aren't breast-feeding.

In most cases, lactation mastitis occurs within the first six to 12 weeks after giving birth (postpartum), but it can happen later during breast-feeding. The condition can cause you to feel run down, making it difficult to care for your baby.

Sometimes mastitis leads a mother to wean her baby before she intends to, but continuing to breast-feed, even while taking an antibiotic for the mastitis, is better for you and your baby.

Symptoms

With mastitis, signs and symptoms can appear suddenly and may include:

  • Breast tenderness or warmth to the touch
  • Generally feeling ill (malaise)
  • Breast swelling
  • Pain or a burning sensation continuously or while breast-feeding
  • Skin redness, often in a wedge-shaped pattern
  • Fever of 101 F (38.3 C) or greater

Although mastitis usually occurs in the first several weeks of breast-feeding, it can happen anytime during breast-feeding. Lactation mastitis tends to affect only one breast.

When to see a doctor

In most cases, you'll feel ill with flu-like symptoms for several hours before you recognize that your breast has an area of tenderness and redness. As soon as you recognize this combination of signs and symptoms, it's time to contact your doctor.

Your doctor will probably want to see you to confirm the diagnosis. Oral antibiotics are usually effective in treating this condition. If you've had mastitis before, your doctor may prescribe antibiotics over the phone. If your signs and symptoms don't improve after the first two days of taking antibiotics, see your doctor right away to make sure your condition isn't the result of a more serious problem.

Causes

Breast-feeding is a learned skill, and poor technique can lead to milk being trapped in the breast, a main cause of mastitis. Other causes include:

  • A blocked milk duct. If a breast doesn't completely empty at feedings, one of your milk ducts can become clogged, causing milk to back up, which leads to breast infection.
  • Bacteria entering your breast. Bacteria from your skin's surface and baby's mouth can enter the milk ducts through a break or crack in the skin of your nipple or through a milk duct opening. Stagnant milk in a breast that isn't emptied enough provides a breeding ground for the bacteria. The antibacterial properties of your milk help protect your baby from the infection.

Risk factors

Risk factors for mastitis include:

  • Breast-feeding during the first few weeks after childbirth
  • Sore or cracked nipples, although mastitis can develop without broken skin
  • Using only one position to breast-feed, which may not fully drain your breast
  • Wearing a tightfitting bra or putting pressure on your breast from using a seatbelt or carrying a heavy bag, which may restrict milk flow
  • Becoming overly tired or stressed
  • Previous bout of mastitis while breast-feeding
  • Poor nutrition

Complications

If mastitis isn't adequately treated, or it's related to a blocked duct, a collection of pus (abscess) can develop in your breast and form a breast mass or area of firmness with thickening. An abscess usually requires surgical drainage. To avoid this complication, talk to your doctor as soon as you develop signs or symptoms of mastitis.

Prevention

To get your breast-feeding relationship with your infant off to its best start — and to avoid complications like mastitis — consider meeting with a lactation consultant. A lactation consultant can give you tips and provide invaluable advice for proper breast-feeding techniques.

Minimize your chances of getting mastitis by following these tips:

  • Fully drain the milk from your breasts while breast-feeding.
  • Allow your baby to completely empty one breast before switching to the other breast during feeding.
  • Change the position you use to breast-feed from one feeding to the next.
  • Make sure your baby latches on properly during feedings.
June 12, 2015
References
  1. Dixon JM. Lactational mastitis. http://www.uptodate.com/home. Accessed April 23, 2015.
  2. FAQ on mastitis. La Leche League International. http://www.llli.org/FAQ/mastitis.html. Accessed April 23, 2015.
  3. Mastitis: Causes and management. World Health Organization. http://www.who.int/maternal_child_adolescent/documents/fch_cah_00_13/en/. Accessed April 23, 2015.
  4. AskMayoExpert. Mastitis. Rochester, Minn.: Mayo Foundation for Medical Education and Research; 2014.
  5. Ferri FF. Mastitis. In: Ferri's Clinical Advisor 2015: 5 Books in 1. Philadelphia, Pa.: Mosby Elsevier; 2015. https://www.clinicalkey.com. Accessed May 28, 2015.