Many patients with liver disease often have “liver function” tests after hospitalization or outpatient visits. What does “liver function” include and how do you understand “liver function” tests? Please take 5 minutes to read the following content carefully to understand the meaning of “liver function” test. ”Liver function tests include: transaminases (including ALT and AST), bilirubin (including indirect bilirubin, direct bilirubin and total bilirubin as the sum of both), albumin, globulin, gamma-glutamyl transpeptidase, and alkaline phosphatase. The following is an introduction for you. 1, transaminases: transaminases in the human body from more sources, in addition to the liver can produce, other than the heart, brain, lungs, muscle, kidney will have transaminases produced, so transaminases are elevated, it must be clear whether it is caused by liver disease, if the patient has previous hepatitis B virus, hepatitis C virus infection or fatty liver, alcoholic liver, or have obvious signs and symptoms of hepatitis (such as poor, bloating, anorexia, liver palm, spider mole If there are also significant abnormalities in bilirubin, albumin, liver ultrasound results, etc., then elevated aminotransferases due to liver inflammation are considered. Usually, in patients with common liver disease, elevated transaminases are mainly ALT, while in patients with alcoholic hepatitis, AST is often the main cause. 2, bilirubin: including two kinds, indirect bilirubin (also known as non-conjugated bilirubin) and direct bilirubin (also known as conjugated bilirubin), the sum of the two is called total bilirubin. Indirect bilirubin is mostly derived from senescent red blood cells, so elevated indirect bilirubin alone is considered to be due to hemolysis, often without liver disease. Direct bilirubin, on the other hand, is derived from indirect bilirubin that is taken up by the liver and processed for synthesis. Direct bilirubin is excreted via the bile ducts to the intestines, and if the ducts in between are narrowed or inaccessible, this can lead to elevated direct bilirubin. In patients with liver disease, often both types of bilirubin are elevated because the raw material (indirect bilirubin) is sufficient, but the processing capacity of the plant (liver) is reduced, which leads to elevated indirect bilirubin; and the reason for elevated direct bilirubin is because the bile ducts are narrowed due to liver inflammation and the direct bilirubin is not excreted smoothly. For liver inflammation, the sum of indirect bilirubin and direct bilirubin (total bilirubin) is an important indicator for evaluating liver damage, and higher bilirubin tends to indicate more severe liver damage and worse prognosis. If the direct bilirubin is elevated, it often indicates bile duct obstruction, which is often caused by bile duct stones and bile duct cancer. 3. Albumin and globulin: Albumin is synthesized by the liver. When liver function is impaired, albumin synthesis decreases, but albumin stays in the body for a longer period of time, so it is only in patients with chronic liver disease (especially cirrhosis) or severe liver damage that albumin decreases significantly. When there is chronic inflammation in the body (not only limited to chronic hepatitis), globulin is elevated. Therefore, in patients with chronic hepatitis, albumin decreases and globulin increases, resulting in a decrease in the ratio of albumin to globulin, referred to as an inverted albumin-to-globulin ratio. 4, γ-glutamyl transpeptidase: The kidney is the most in human body, followed by pancreas and liver, and glutamyl transpeptidase in normal human serum mainly comes from liver. For liver disease, elevated glutamyl transpeptidase often indicates: (1) cholestasis, (2) alcoholic liver disease, (3) primary liver cancer, (4) primary biliary cirrhosis. 5, alkaline phosphatase: Alkaline phosphatase is widely distributed in human liver, bone, intestine, kidney and placenta. Elevated alkaline phosphatase is often indicative of related organ disease. For the liver, it often indicates cholestasis, cirrhosis, bile duct malignant disease, etc.