Breast Infection

What is a breast infection?

An infection in the tissue of the breast is called mastitis. This condition is most common in women who are breast-feeding. You may have both general symptoms of illness and breast symptoms including:

  • achy, flulike feeling
  • fever
  • chills
  • lump in the breast
  • headache
  • breast pain
  • breast redness
  • breast firmness
  • nipple or areolar pain
  • trouble getting milk to flow.

Call your healthcare provider promptly if you have any symptoms of a breast infection. The sooner you start treatment, the sooner you will feel better. Prompt treatment may prevent complications, such as a breast abscess (a pocket of pus requiring drainage).

What is the cause?

Breast infections are usually caused by bacteria. Bacteria are normally present on the nipple and in a baby's mouth. They can enter the breast through a cracked nipple or the milk ducts and cause a breast infection. The nipple injury may be caused by a baby incorrectly latching on to the breast.

Many factors can make a breast-feeding mother susceptible to a breast infection. One of the main factors is inadequate drainage of milk from the breasts. Poor draining can occur by letting too much time pass between feedings. Also, milk may not drain well if a duct is clogged, or a tight-fitting bra may decrease milk flow.

Injury to the breast can increase the risk of a breast infection. The injury may be caused by an older baby biting the nipple or kicking the breast. Use of a breast pump that generates excessive vacuum also can injure the breast.

Exhaustion may contribute to a breast infection. For example, returning to work, not getting enough sleep, and having house guests may tire a new mother.

What is the treatment?

  • Take all of the antibiotic your healthcare provider prescribes even if you feel much better after a few days. Mastitis is usually treated with an antibiotic for 10 to 14 days. Antibiotics kill bacteria, even the good ones in the gut. The loss of these “good” bacteria can lead to diarrhea, thrush and other yeast infections. Talk with your provider about taking a good quality probiotic to prevent these problems.
  • Rest and stay in bed as much as possible for the first 24 hours. Get all the help you can for at least the next day.
  • Drink plenty of fluids, especially if you have a fever.
  • Eat a healthy diet that includes a variety of fruits and vegetables. Good nutrition helps the body’s immune system,
  • Take medicine for the pain if needed. You may need pain medicine during the first 2 days of your illness. Ibuprofen is a good choice for nonprescription pain medicine. Only very small amounts of ibuprofen are excreted in breast milk.
  • Nurse more often, especially from the side that is infected, to keep your breasts well drained.

    You do not have to wean your baby if you have a breast infection. In fact, you should nurse more often. You may need to put moist heat on the affected breast before nursing to help start milk flow. For example, put a warm washcloth on the breast, take a warm shower, or submerge the breast in a warm bath. You can begin feedings on the side that is not infected and then move your baby to the infected breast once your let-down has been triggered.

    If you are pumping milk for a sick or premature hospitalized baby when you develop mastitis, discard the milk collected from the infected side until you feel well.

  • Pump your breasts if necessary. If nursing your baby is too painful or doesn't relieve your breast fullness, you may need to get a fully automatic breast pump to comfortably and efficiently drain your breasts.

    You may need to use a fully automatic breast pump if:

    • The infected breast is still not draining well even though you have followed the treatment suggestions.
    • Nursing your baby from the infected breast is too painful.
    • Your baby refuses to nurse from the infected breast.

When should I call the healthcare provider?

Call YOUR healthcare provider during office hours if:

  • Your symptoms are not better within 48 hours after you start taking antibiotics.
  • Tender breast swelling develops that is not relieved by nursing.

Call your BABY'S healthcare provider during office hours if:

  • You think your milk supply is decreasing.
  • Your baby shows any signs of illness such as fever, poor feeding, excess sleepiness, irritability, trouble breathing, or a rash. Call any time if you are worried.
  • Your baby develops a diaper rash while you are taking antibiotics. The rash may be due to a yeast infection and may need treatment.
Written by Marianne Neifert, MD, and the clinical staff of The Lactation Program, Rose Medical Center, Denver, CO. 303-377-3016.
Published by RelayHealth.
Last modified: 2011-02-09
Last reviewed: 2010-11-22
This content is reviewed periodically and is subject to change as new health information becomes available. The information is intended to inform and educate and is not a replacement for medical evaluation, advice, diagnosis or treatment by a healthcare professional.
© 2011 RelayHealth and/or its affiliates. All rights reserved.