The most common type of breast infection is lactational mastitis. With this condition, which occurs when a woman is breastfeeding, a woman's nipples become cracked and sore allowing bacteria from the baby's mouth to enter the ducts and rapidly multiply in the milk. Occasionally, infection also arises from a blocked milk duct. In both cases, the breast becomes hard, reddened, hot, and painful. Your physician may suggest trying to unblock the duct with warm compresses and massage.
Nonlactational mastitis is similar to lactational mastitis but occurs in nonlactating women.
In some cases, this condition occurs in women who have had lumpectomies followed by radiation therapy, in women with diabetes, or in women whose immune systems are depressed. While this condition is rare, it is usually accompanied by high fever and headache and treated with antibiotics. Consult your physician for a diagnosis and treatment. Chronic subareolar abscess is the second most common breast infection, although it occurs infrequently. Once believed to be a blocked duct, physicians now believe that the glands that make sebaceous material around the nipple become infected.