Liver function tests are one of the most common biochemical tests used in clinical and physical examinations, and often consist of different items. However, the functions of the liver are very complex, and its main functions include synthesis, metabolism, digestion, detoxification, etc. There are also different indicators to reflect this in clinical practice, for example, the albumin in liver function tests reflects the synthesis function of the liver. Most of the liver function indicators are various enzymes, especially the more commonly used is glutathione, this enzyme mainly exists mainly in the liver cell plasma, under normal circumstances rarely into the blood circulation, but when the liver cell inflammation, cell membrane permeability increases, this enzyme will move from intracellular to extracellular, resulting in increased blood concentration, therefore, elevated glutathione generally means liver inflammation. Other enzymes are also associated with liver inflammation or obstruction of the intrahepatic bile ducts. When liver disease is mild, only 1-2 indicators may be abnormal, and there are usually no specific symptoms at this time, and there may be only a little weakness and feeling easier to exert than before; when liver disease progresses further, more indicators may be abnormal, and patients may also experience nausea, aversion to grease, jaundice and other symptoms at this time. In terms of liver inflammation judgment, liver function tests can really respond to liver traces changes sensitively, so it becomes the most commonly used indicator in medical examination. Most liver function indicators reflect liver inflammation indicators, and the only real liver synthesis function is the albumin level, but this indicator is also affected by the patient’s nutritional status and other factors. For example, the prothrombin time, which is an indicator of how quickly a person can clot after bleeding, is an indicator of how quickly a person can clot after bleeding. Since most clotting factors are synthesized in the liver, when liver function is impaired, the body does not produce enough clotting factors to cause bleeding, because the half-life of some clotting factors is much shorter than that of albumin. Therefore, when liver function is impaired, this seemingly unrelated indicator will be the first to show abnormalities, thus helping the doctor to more accurately determine the severity of the patient’s impaired liver function. Blood ammonia is an indicator of the liver’s metabolic function, because ammonia produced from food and urea decomposed by intestinal bacteria is absorbed intravenously and first detoxified by the liver into urea, which is less toxic to humans. There are also some tests that can detect liver metabolic function, such as indocyanine green excretion test, which can reflect liver metabolic function more objectively. All of the above tests can reflect recent liver damage. For a patient with chronic liver disease, the doctor may be more concerned about whether the patient has severe liver fibrosis, cirrhosis and possible hepatocellular carcinoma after a long period of liver disease. These tests mainly include non-invasive liver fibrosis tests such as Fibroscan, abdominal liver ultrasound, gastroscopy, CT and MRI, and sometimes even liver aspiration pathology is required.