Overview
What Mastitis Is and Why It Develops
Lactational mastitis is inflammation of breast tissue during breastfeeding or milk expression.
Lactational mastitis is inflammation of breast tissue during breastfeeding or milk expression. The process commonly starts with milk stasis: milk is not draining adequately, a duct becomes obstructed, and surrounding tissue becomes swollen. That edema further narrows the drainage pathway, so pain, tenderness, warmth, and localized erythema can intensify. Inflammation does not automatically mean bacterial infection. Bacteria may enter through cracked or traumatized nipple skin, with *Staphylococcus aureus* the most common organism identified. This explains why a painful, inflamed breast can initially improve with measures that restore milk drainage, while persistent or systemic illness may require antibiotics. The pattern is usually unilateral because the obstruction and tissue inflammation are localized to one breast. A practical nurse should therefore connect three findings rather than treating them as isolated complaints: a focal breast change, the mother’s systemic condition, and the effectiveness of milk removal.
