Clinically, blisters on the upper lip can not be judged only by the liver fire or heart fire, need to be combined with other symptoms of the patient to determine a comprehensive. Liver fire and heart fire can cause blisters on the upper lip. Such as liver fire caused by blistering on the upper lip, often accompanied by irritability, insomnia, repeated mouth ulcers, swollen gums, dry mouth, short urine (urine volume, dark yellow), and so on, and severe cases can even appear manic delirium (gibberish), confusion, vomiting blood, nosebleeds, and so on. If the heart fire caused by blistering upper lip, often accompanied by headache, dizziness, red face, red eyes, dry mouth, bitter mouth, sore throat, pain in the abdomen and ribs, yellow urine, constipation, and even vomiting blood, etc., and women may also have menstrual disorders, irritability, temper, and so on. If the symptoms of blistering on the upper lip are not relieved for a long time or accompanied by other discomforts, consult a doctor in time to identify the cause and carry out targeted treatment.