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By Mayo Clinic staffMastitis is an infection of the breast tissue that causes pain, swelling and redness of the breast. Mastitis most commonly affects women who are breast-feeding, although in rare circumstances this condition can occur outside of lactation.
Often, mastitis occurs within the first six weeks after birth (postpartum), but it can happen later during breast-feeding. The condition can leave you feeling exhausted and rundown, making it difficult to care for your baby.
Sometimes mastitis leads a mother mistakenly to wean her baby before she intends to. But you can continue breast-feeding while you have mastitis.