A breast infection usually results due to the invasion of the breast by bacteria, resulting in inflammation, and is called as MASTITIS. Infections of the breast most commonly occur one to three months post-delivery, but can also occur in postmenopausal women. Mastitis occurs most commonly during the time of breastfeeding. It often tends to occur when bacteria enter through a crack in the nipple when the baby breastfeeds. Engorgement and incomplete emptying of the best may worsen the symptoms further. Chronic mastitis occurs mostly in women who are not breastfeeding and is seen commonly after menopause.