Left liver shrinkage in hepatitis B patients refers to the shrinkage of the left lobe of the liver, which is more serious. The left liver of hepatitis B patients shows atrophy and the structural function of the liver is destroyed, which may be caused by cirrhosis and insufficient hepatic artery-portal vein blood supply. 1. Cirrhosis: it is a chronic, progressive, diffuse liver disease caused by many reasons, including digestive system, blood system and other multi-systemic lesions. Serious complications may occur in the later stages of cirrhosis, such as gastrointestinal bleeding, infections, hepatic encephalopathy, hepatorenal syndrome and so on. 2. Insufficient hepatic artery-portal vein blood supply: the liver has dual blood supply, including portal vein and hepatic artery. Insufficient hepatic artery-portal vein blood supply may cause abnormalities in ultrastructure and metabolic function of hepatocytes, and imbalance of glucose metabolism and amino acid metabolism in the body. Therefore, patients with hepatitis B whose left liver shrinkage is remaining normal should go to the hospital as soon as possible to find out the cause of the disease, and carry out standardized treatment under the guidance of doctors.