Diagnostic criteria for acute liver failure include clinical symptoms, bilirubin level, prothrombin activity, and pathologic examination. 1. Clinical symptoms: accompanied by fatigue, nausea, vomiting and other digestive symptoms. 2. Bilirubin level: total bilirubin is often ≥171umol/L, and jaundice deepens progressively. 3. Plasminogen activity: ≤40%, obvious bleeding tendency. 4. Pathologic examination: progressive shrinkage of the liver is seen. The volume of hepatocellular necrosis is larger than 2/3 of the liver parenchyma. If the patient starts the disease acutely and develops hepatic encephalopathy of 2nd degree or above within 2 weeks with the above manifestations, it can be diagnosed as acute liver failure. If acute liver failure is diagnosed, the patient should be admitted to the hospital immediately to control the condition.