The five tests of liver function mainly include glutathione, glutamic oxalacetic transaminase, total bilirubin, direct bilirubin and indirect bilirubin. Aminotransferases mainly reflect the presence of liver cell damage. Bilirubin is a reflection of the liver’s ability to take up, convert and excrete bilirubin. If these indicators are significantly elevated, it is likely that liver lesions are present and further tests are needed to clarify the cause. However, the five liver function tests have certain limitations, even if the values of the tests are normal, it does not mean that there is no disease state, many liver diseases may not cause abnormal liver function tests in the early stage, and even a full set of liver function tests may not show significant abnormalities. Therefore, for patients with previous liver disease, further liver function tests should be performed, as well as further liver imaging and even tumor markers.