Mastitis is a painful breast inflammation that most often hits nursing moms in the first three months after delivery. It can come on fast, so knowing the early signs helps you call for help before it turns into an abscess. The first thing women usually feel is a sore, heavy spot in one breast. It may start as a small tender lump or just a dull ache that gets worse when the baby nurses. The area quickly becomes red, warm, and swollen, and the redness can spread outward in a wedge-shaped patch. Many moms describe “flu” feelings: chills, body aches,... Learn more