by Rick Alan
Mastitis is painful swelling and redness in the breast. It is most common among women who are breastfeeding. It usually occurs in one breast at a time, but it can occur in both breasts at the same time.
Mastitis can occur in women who are not breastfeeding. However, this fact sheet will focus on symptoms and treatment of mastitis that occurs with breastfeeding.
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Mastitis is often caused by breast milk trapped in a milk duct. The trapped breast milk can irritate the tissue around it and cause swelling and pain.
Mastitis can also be caused by bacteria. The bacteria can enter the breast through the milk duct or cracks in the skin of nipple. Once the bacteria enter the tissue, it can grow and cause an infection.
Factors that may increase your chances of mastitis:
Mastitis may cause:
You will be asked about your symptoms and health history. A physical exam will be done. If the diagnosis is uncertain, or if mastitis recurs, your doctor may do:
Other conditions may cause similar symptoms. Your doctor may want to do tests to rule these out. Options may include:
Treatment may include:
Pain and swelling can be caused by the blocked milk. Clearing the blockage can help. To clear blocked breast ducts try the following:
To help reduce pain and swelling in the breast:
Antibiotics may be needed if there is an infection. They can cure it and reduce the risk of complications. Your doctor will recommend an antibiotic that is safe while breastfeeding.
An infection can sometimes lead to a pocket of pus. This pocket may not respond to antibiotics. It may need to be drained by the doctor.
To help reduce your chances of mastitis:
Office on Women's Health
The American Congress of Obstetricians and Gynecologists
Canadian Women's Health Network
Society of Obstetricians and Gynaecologists of Canada
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Mastitis. Family Doctor—American Academy of Family Physicians website. Available at: https://familydoctor.org/condition/mastitis. Updated April 1, 2014. Accessed April 17, 2018.
Masitis. EBSCO DynaMed website. Available at: https://www.dynamed.com/topics/dmp~AN~T116795/Mastitis . Updated March 15, 2016. Accessed April 17, 2018.
Spencer J. Management of mastitis in breastfeeding women. Am Fam Physician. 2008;78(6):727-731.
11/5/2014 DynaMed's Systematic Literature Surveillance https://www.dynamed.com/topics/dmp~AN~T116795/Mastitis : Amir L, The Academy of Breastfeeding Medicine Protocol Committee. ABM clinical protocol #4: mastitis, revised March 2014. Breastfeed Med. 2014;9(5):239-243.
Last reviewed March 2018 by
EBSCO Medical Review Board
Marcie L. Sidman, MD
Last Updated: 7/12/2018