Breast Infection
(Mastitis)

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Medical Author:

Suzanne R Trupin, MD

Suzanne R Trupin, MD

Dr. Suzanne Trupin is a Clinical Professor of Obstetrics and Gynecology at the University Of Illinois College Of Medicine at Urbana-Champaign. She graduated from Stanford University and completed her medical training at New York Medical in Valhalla, New York. She received her residency training at the University of Southern California Women's Hospital in Los Angeles, California. She is Board-Certified by the American Board of Obstetrics and Gynecology.

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Medical Editor:

Melissa Conrad Stöppler, MD, Chief Medical Editor

Melissa Conrad Stöppler, MD, Chief Medical Editor

Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

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• Breast Infection Overview
• Breast Infection Causes
• Breast Infection Symptoms
• When to Seek Medical Care
• Exams and Tests
• Breast Infection Treatment
• Self-Care at Home
• Medications
• Surgery
• Next Steps
• Follow-up
• Prevention
• Outlook
• Support Groups and Counseling
• For More Information
• Web Links
• Synonyms and Keywords
• Authors and Editors
• Viewer Comments: Breast Infection - Cause
• Viewer Comments: Breast Infection - Symptoms

Breast Infection Overview

Mastitis is an infection of the tissue of the breast that occurs most frequently during the time of breastfeeding. This infection causes pain, swelling, redness, and increased temperature of the breast. It can occur when bacteria, often from the baby's mouth, enter a milk duct through a crack in the nipple. This causes an infection and painful inflammation of the breast.

Breast infections most commonly occur one to three months after the delivery of a baby, but they can occur in women who have not recently delivered as well as in women after menopause. Other causes of infection include chronic mastitis and a rare form of cancer called inflammatory carcinoma.

• The breast is composed of several glands and ducts that lead to the nipple and the surrounding colored area called the areola. The milk-carrying ducts extend from the nipple into the underlying breast tissue like the spokes of a wheel. Under the areola are lactiferous ducts. These fill with milk during lactation after a woman has a baby. When a girl reaches puberty, changing hormones cause the ducts to grow and cause fat deposits in the breast tissue to increase. The glands that produce milk (mammary glands) that are connected to the surface of the breast by the lactiferous ducts may extend to the armpit area (axilla).

• A breast infection that leads to an abscess (a localized pocket or collection of pus) is a more serious type of infection. If mastitis is left untreated, an abscess can develop in the breast tissue. This type of infection may require surgical drainage.