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Symptoms and Signs of Breast Infection

Doctor's Notes on Breast Infection

Breast infection (also termed mastitis) is infection of the tissue in the breast, in most individuals, due to a bacterial infection. Signs and symptoms of breast infections are redness of breast tissue, pain and warmth of the breast, body aches, fatigue, fever or chills, and breast engorgement. Some individuals may develop tender, somewhat mobile masses beneath the skin or deeper in the breast tissue (abscesses). Abscesses, pus drainage from the nipple or any other areas on the breast and/or persistent fever for about 2 to 3 days are signs and symptoms of a more serious breast infection.

Bacteria normally found in a baby’s mouth or on the nipple of a woman is breast feeding, can enter milk ducts for small cracks in the skin and rapidly multiply. Streptococcal and/or staphylococcal organisms are the most frequent types of bacteria that cause breast infections. Other conditions that alter the milk ducts in the breast (for example, hormonal changes, breast cancer) can create an environment that encourages or causes bacteria to be able to proliferate and cause breast infections.

Medical Author:
Medically Reviewed on 3/11/2019


Kasper, D.L., et al., eds. Harrison's Principles of Internal Medicine, 19th Ed. United States: McGraw-Hill Education, 2015.