Severe hepatitis is the most serious clinical type of hepatitis, with massive necrosis of liver cells as the basic pathological feature. Generally, people only know the horror of liver cancer, but in fact, severe hepatitis is more horrible than liver cancer. Heavy hepatitis has heavy disease, fast development, many complications and high mortality rate. If not treated in time, it can lead to death in a few days or weeks, and the mortality rate can be over 80%. There are many causes of severe hepatitis, which can be divided into viral infection, drug poisoning, toxic poisoning, alcohol poisoning, bacterial infection, and metabolic disorders. Among them, viral hepatitis, especially hepatitis B, is the most common. And the incidence of severe hepatitis B accounts for about 1% of patients with hepatitis B typeitis, with the majority of young adults. The clinical types of severe hepatitis can be divided into three types: (1) acute heavy: also known as fulminant hepatitis. The disease develops rapidly, with rapid onset of mental and neurological symptoms within 10 days, ranging from irritability and confusion to deep coma. The liver shrinks progressively, the prothrombin activity decreases abruptly, and peritonitis, hemorrhage, cerebral edema and brain herniation may appear at a later stage. The disease is critical and the prognosis is poor. (2) Subacute heavy disease: The disease starts within 10 days and 8 weeks, mainly with extreme weakness, marked loss of appetite, severe nausea and aversion to oil, frequent vomiting, severe abdominal distension and ascites. Jaundice progressively deepens, liver odor gradually appears, obvious bleeding tendency and psycho-neurological manifestations may appear, and liver and kidney function tends to fail. The prognosis is poor because of the frequent complications of various infections. Some patients can be expected to recover after treatment, but easily develop into post-necrotic cirrhosis. (3) Chronic heavy: on the basis of chronic hepatitis or hepatitis cirrhosis, the condition deteriorates sharply. The occurrence of various comorbidities in severe hepatitis, which in turn aggravate the disease and promote the death of the patient. The common comorbidities of severe hepatitis are: (1) hepatic encephalopathy; (2) electrolyte disorders and acid-base imbalance; (3) bleeding: gingival bleeding, epistaxis, subcutaneous bleeding, gastrointestinal bleeding such as vomiting blood and blood in the stool due to severe impairment of the patient’s bleeding and coagulation mechanisms; (4) infection: patients are highly susceptible to bacterial and mycotic infections due to immune deficiency, with abdominal, intestinal and pulmonary infections being the most common. (5) hepatic and renal syndrome, once combined with hepatic and renal syndrome, the prognosis of heavy hepatitis is poor, and patients often die; (6) cerebral edema: respiratory failure into encephalopathy can lead to respiratory arrest. The pathogenesis of severe hepatitis is not completely clear, and there is no special treatment, but the disease can be aggravated by untimely treatment, overexertion, alcohol consumption, infection, improper medication, etc. The survival rate of patients admitted to hospital in the early, middle and late stages of the course of severe hepatitis is very different, and the survival rate of patients in the early and middle stages is significantly higher than those treated in the late stage. Currently, the treatment of severe hepatitis is mainly comprehensive, especially with the aid of artificial liver support system, the death rate of severe hepatitis can be reduced to less than 20%-30%. With the development of medicine, liver transplantation provides an important tool for the treatment of severe hepatitis.