Breast swelling and pain with overflow and smell may be acute mastitis, breast hyperplasia, breast tumor and other diseases, it is recommended to go to the hospital for examination. 1. Acute mastitis: most common in postpartum breastfeeding women, milk stagnation and bacterial invasion can lead to breast swelling and pain, inflammation, accompanied by abscess formation, there may be overflow and taste. 2. Breast hyperplasia: such as cystic hyperplasia of the breast, most common in middle-aged women, may have one or both sides of the room swelling and pain and lumps, a few patients have plasma or plasma blood nipple discharge. 3. Breast tumor: such as intraductal papilloma, there may be bloody dark brown or yellow nipple discharge, but the lump is not easy to touch. If you feel uncomfortable in your breasts, you should go to the hospital to find out the cause of the disease and treat it in time.