The liver is the body’s chemical factory, and the general health of the liver can be reflected by testing some basic indicators. 1. Transaminase. Transaminase is an essential “catalyst” in the metabolic process of the human body, which usually “lives” in the liver cells and will not come out under normal circumstances. However, if the liver cells are damaged or ruptured, transaminase will be released, and the physical examination report will show elevated indicators. The more damage there is, the higher the transaminases will go. When liver cells are destroyed to a certain extent, liver function will be affected. Normal ranges: AST (15-40 units/liter); ALT (9-50 units/liter). Causes of abnormality: If it is mildly elevated, it is usually not a cause for concern and is mostly related to physiological factors. Review the test within half a month, and if it is still high, further examination should be done to find out the cause. Physiological reasons mainly include staying up late, fatigue, grease, alcohol consumption, strenuous exercise, etc.. If the value is higher than 100, further examination should be done to find out if there are other diseases, such as fatty liver. If the value is very high, reaching 300 or even 600 units, it should be combined with further examination (hepatitis B virus DNA test, ultrasound, CT, tumor markers, etc.) to consider whether there is acute inflammation, liver injury, tumors, cholelithiasis and so on. 2. Bilirubin. Bilirubin comes from necrotic red blood cells and is metabolized in the liver. If the liver function is abnormal, it will affect the metabolism of bilirubin, which will lead to high bilirubin in the serum. This indicator reflects the metabolic capacity of the liver. Normal range: total bilirubin (3~21 micromol/liter); direct bilirubin (0~7 micromol/liter). Causes of abnormality: Most are mildly elevated on physical examination, reflecting the reduced ability of the liver to metabolize bilirubin. Possible causes include fatty liver, chronic liver disease (hepatitis), and trauma to the liver. Abnormalities in this indicator reflect long-term overload of the liver, which can cause liver fibrosis or even cirrhosis in the long run, so it is important to pay attention to it, actively search for the primary cause of the disease, eat less greasy food, and reduce the burden on the liver. If dynamic observation reveals that the bilirubin is abnormal for a long time, but it is around 30 every time, there is no symptom such as jaundice, and the cause cannot be found, it may be Gilbert’s syndrome. If the total bilirubin is very high, three times higher than the upper limit of normal value or greater than 50 micromol/liter, jaundice can be seen from the naked eye, it may be caused by biliary obstruction, sclerosing cholangitis, biliary malignant tumors, etc., and it should be detected and treated early. 3.Serum albumin and prothrombin time. Reflect the synthesizing ability of liver. Normal range: 40~55g/l for the former, 9.4~12.5 seconds for the latter. Abnormal causes: under normal diet, long-term albumin reduction and prolongation of prothrombin time indicate the gradual reduction of normal hepatocytes, poor function of hepatocytes to synthesize proteins and coagulation factors, diminished reserve function of the liver, and chronic hepatitis B, cirrhosis, and liver failure or hematological disorders and so on. 4.Liver tumor markers. Tumor markers related to liver include alpha-fetoprotein (AFP), glycoconjugate antigen-199 (CA-199), carcinoembryonic antigen (CEA). Normal range: AFP (0-7 micrograms/liter), CA-199 (0-39 units/mL), CEA (≤5 ng/mL). Reasons for abnormality: AFP is a liver-specific metabolic indicator, and anything above 7 needs to be reviewed. If it is below 200, hepatitis should be ruled out first, and if it is in the active stage of hepatitis B or C, this indicator will also be high. After hepatitis is ruled out, most of the elevation is caused by liver tumors; if it is between 200~400, it tends to be hepatocellular carcinoma; if it is greater than 400, it is likely to be hepatocellular carcinoma.CA199 is mostly related to tumors of biliary origin, reflecting that intrahepatic cholangiocellular carcinoma is more sensitive than AFP. Carcinoembryonic antigen, whose elevation is mostly associated with tumors of gastrointestinal origin, is considered to be metastatic to the liver if ultrasound shows multiple nodules in the liver at the same time.