To determine whether you have a milk blockage or mastitis, you can use symptom analysis, cause and other methods to determine, but the accuracy of your own judgment is low, you should be based on the results of the doctor’s examination. 1. Symptoms: Symptoms of breastfeeding include breast swelling, localized breast redness, and breast sensitivity. The symptoms of mastitis are different from the symptoms of breast blockage, there will be localized breast redness, swelling, hardness, pain and other symptoms, but also may be accompanied by nipple pus secretion, general fever and other phenomena. 2. Causes: Mastitis is mainly caused by the lack of smoothness of the milk ducts, the milk is blocked in a certain place, forming a hard lump. The cause of mastitis may be related to milk stagnation, bacterial infection and other conditions. During breastfeeding, when there is localized redness, swelling, heat and pain in the breast or a lump, you need to consult a doctor for examination in a timely manner, and you can’t judge on your own.