Mastitis is an infection of the breast tissue that results in breast pain, swelling, warmth and redness of the breast. If you have mastitis, you might also experience fever and chills. Mastitis most commonly affects women who are breast-feeding (lactation mastitis), although sometimes this condition can occur in women who aren't breast-feeding.
In most cases, lactation mastitis occurs within the first three months after giving birth (postpartum), but it can happen later during breast-feeding. The condition can leave you feeling exhausted and run-down, making it difficult to care for your baby.
Sometimes mastitis leads a mother to wean her baby before she intends to. But you can continue breast-feeding while you have mastitis.