Pathophysiology
Clinical meaning
Mastitis is an infection of the breast tissue that most commonly occurs during lactation, typically within the first 6 weeks postpartum. Bacteria - most often Staphylococcus aureus - enter through cracked or damaged nipples and infect the milk ducts and surrounding tissue. Milk stasis from poor latch, missed feedings, or blocked ducts provides a medium for bacterial growth. The affected breast becomes erythematous, warm, swollen, and painful. The mother develops systemic symptoms including fever (38.5C or higher), chills, malaise, and flu-like symptoms. If untreated, mastitis can progress to breast abscess requiring incision and drainage. The condition is distinguished from engorgement (bilateral, no fever) and blocked duct (localized lump, no systemic symptoms). Continued breastfeeding is encouraged to prevent milk stasis from worsening the infection.