Diagnosis

Your doctor will do a thorough physical exam and ask you about your signs and symptoms. A culture of your breast milk might help your doctor determine the best antibiotic for you, especially if you have a severe infection.

A rare form of breast cancer — inflammatory breast cancer — also can cause redness and swelling that could initially be confused with mastitis. Your doctor may recommend a mammogram or ultrasound or both. If your signs and symptoms persist even after you complete a course of antibiotics, you may need a biopsy to make sure you don't have breast cancer.