Liver enzyme tests, formerly called liver function tests (LFTs), are a group of blood tests that detect inflammation and damage to the liver. They can also check how well the liver is working. Liver enzyme testing includes ALT, AST, alkaline phosphatase; true liver function tests (LFTs) include PT, INR, albumin, and bilirubin.
Incidence and Mortality
Estimated new cases and deaths from liver and intrahepatic bile duct cancer in the United States in 2013:
New cases: 30,640.
Hepatocellular carcinoma (HCC) is relatively uncommon in the United States, although its incidence is rising, principally in relation to the spread of hepatitis C virus (HCV) infection. HCC is the most common solid tumor worldwide and the third leading cause of cancer-related deaths.[3,4]
Both local extension...
Most often, a liver test panel is ordered as a routine lab test. Many doctors check the liver in new patients or during annual physicals.
Your doctor may conduct liver enzyme and liver function tests if:
You are taking a medication that can harm the liver
You have liver disease
You have symptoms of liver or bile system disease (abdominal pain, nausea and vomiting, or yellow skin)
You drink alcohol excessively
Liver tests may be done together in a panel or tested separately.
Liver Enzyme Tests: ALT and AST
The liver filters and processes blood as it circulates through the body. It metabolizes nutrients, detoxifies harmful substances, makes blood clotting proteins, and performs many other vital functions. The cells in the liver contain proteins called enzymes that drive these chemical reactions.
When liver cells are damaged or destroyed, the enzymes in the cells leak out into the blood, where they can be measured by blood tests. Liver tests check the blood for two main liver enzymes:
Aspartate aminotransferase (AST), formerly called SGOT. The AST enzyme is also found in muscles and many other tissues besides the liver.
Alanine aminotransferase (ALT), formerly called SGPT. ALT is almost exclusively found in the liver.
If ALT and AST are found together in elevated amounts in the blood, liver damage is most likely present.