An LFT lab tes is a liver function test performed by analyzing a blood sample to evaluate the functioning of the liver and detect the presence of various liver diseases. LFT blood tests may also be used to monitor the body’s response to a specific course of treatment of diseases like cirrhosis or hepatitis. However, not all LFT lab tests measure the liver’s function. An LFT blood tes may measure the levels of proteins like albumin and globulin to check for blood disorders, gastrointestinal problems like gall stones, or confirm a diagnosis of several diseases such as Hodgkin’s disease or collagen diseases.
When the red blood cells in the body break down, bilirubin is released. The liver normally removes the toxins from the bilirubin and helps to excrete it from the body. High levels of bilirubin in the blood and yellow discoloration of the skin indicate that the liver is not functioning well. The high level could also be an indication of a blockage in the bile tract or a tumor in the liver, bile tract, or gall bladder.
High levels of GGT or gamma glutamyl transpeptidase in the LFT lab results may mean a malfunction in the bile duct, since this is an enzyme produced in the bile duct. Similarly, alkaline phosphatase is another enzyme produced in the bile duct and elevated levels of ALK Phos as well GGT may point to inflammation, blockage, or injury to the bile duct. However, it must be remembered that smokers normally have higher levels of both enzymes than non-smokers. Levels of transaminases aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in the blood are checked to confirm if there is an inflammation or damage to the liver. The ratio of the levels of AST and ALT also give medical practitioners clues about the damage to the cells of the liver, particularly in cases of hepatitis, cirrhosis caused by alcohol abuse, etc.
LFT lab values may include a platelet count, particularly when the diagnosis indicates cirrhosis. Platelets are useful in the formation of blood clots at the time of an injury to stop the bleeding. Prothrombin time is the time taken for the blood to clot, and in cases of cholestatic liver diseases, where the platelet count is seen to be low, the clotting time may be longer than normal, leading to excessive bleeding. Diagnosis of liver diseases through physical examination and patient symptoms and history can be confirmed by these LFT lab tests.