The first symptoms of mastitis are swollen and tender breasts, redness and swelling of the infected area, fever, chills, headache, nausea and vomiting. New mothers can take care of themselves by applying hot compresses and massages, while going to the hospital for treatment usually takes about a week to heal. Since mastitis only infects the breast tissue and has nothing to do with breast milk, it will not infect the baby and you can continue to breastfeed. You should also use antibiotics and other medications that do not affect children.