The 12 liver function tests look at aminotransferases, bilirubin, serum proteins and other indicators.
1. Transaminases: A group of enzymes, usually called transaminases, are alanine transaminase and glutamic transaminase. These two enzymes are found inside the liver cells, and when the liver cells are damaged they will enter the bloodstream and show elevated aminotransferases. Therefore, they are a sign of liver damage. The other types are alkaline phosphatase and glutamyl transpeptidase, and their elevation generally indicates damage to the bile ducts.
2. Bilirubin: Bilirubin is a product of normal metabolism after the death of blood cells in the human body. The death of red blood cells in the blood produces indirect bilirubin, which is converted into direct bilirubin by the liver. Elevated bilirubin can cause jaundice.
3. Serum proteins: In the laboratory tests, the two main proteins are serum total protein and serum albumin. Contrary to the first two, most protein abnormalities are on the low side. Protein is the most informative indicator of liver function. If liver function is impaired, the liver’s ability to synthesize protein decreases, leading to a decrease in protein levels in the blood. With a decrease in serum protein content, osmotic pressure decreases and water moves out of the circulation into the tissues. This is how ascites, which is often associated with cirrhotic patients, arises.
These are the three main categories of indicators that reflect liver function, and more other evidence is needed for the doctor to make a clinical diagnosis. For example, in hepatobiliary surgery, the doctor will also refer to the presence of ascites, symptoms of hepatic encephalopathy, and blood clotting function.
If you feel unwell, seek medical attention and follow the doctor’s instructions.