What are some common liver tests?
A series of blood tests can often
find out if the liver is inflamed, injured, or working normally. These tests can also
tell the difference between acute and chronic liver disorders. And they can tell the
difference between hepatitis (infection or inflammation of the liver) and cholestasis
(problems with the flow of bile).
The most common blood tests are
below.
Liver function tests
-
Serum bilirubin test. This test measures the levels of
bilirubin in the blood. Bilirubin is made by the liver and is excreted in the
bile. High levels of bilirubin may mean there is a blockage of bile flow or a
problem with how the liver processes bile.
-
Serum albumin test. This test is used to measure the
level of albumin. Albumin is a protein in the blood. The test may help in the
diagnosis of liver disease. Low levels of albumin may mean the liver is not
working normally.
-
International normalized ratio (INR). This used to be
known as the prothrombin time (PT) test. This test measures how long it takes for
blood to clot. Blood clotting needs vitamin K and a protein that is made by the
liver. Blood that takes a long time to clot may mean liver disease or low levels
of certain clotting factors.
Liver enzyme tests
-
Serum alkaline phosphatase test. This test is used to
measure the blood level of an enzyme called alkaline phosphatase. This enzyme is
found in many tissues. The highest amounts are in the liver, biliary tract, and
bones. This test may be done to check liver function. And it may be done to find
liver lesions that may cause bile blockage, such as tumors or abscesses.
-
Alanine transaminase (ALT) test. This test measures the
level of alanine aminotransferase. This is an enzyme found mostly in the liver. It
is released into the bloodstream after acute liver cell damage. This test may be
done to check liver function. Or it may be done to check on the treatment of acute
liver disease, such as hepatitis.
-
Aspartate transaminase (AST) test. This test measures
the level of aspartate transaminase. This is an enzyme that is found in the liver,
kidneys, pancreas, heart, skeletal muscle, and red blood cells. This enzyme is
released into the bloodstream after acute liver cell damage.
-
Gamma-glutamyl transpeptidase (GGT) test. This test
measures the level of gamma-glutamyl transpeptidase. This is an enzyme that is
made in the liver, pancreas, and biliary tract. This test is often done to check
liver function, to give information about liver diseases, and to see if a person
has had alcohol.
-
Lactic dehydrogenase test. This test can find tissue
damage and may help in the diagnosis of liver disease. Lactic dehydrogenase is a
type of protein. It is also called an isoenzyme. It is involved in the body's
metabolic process. But this is a very nonspecific liver test. It is rarely used
for liver disease assessment.
Other diagnostic tests
Other diagnostic liver tests may be done if a specific disease is
suspected. These tests include:
-
Alpha-fetoprotein (AFP) test. Alpha-fetoprotein is a
blood protein made by fetal tissue and by tumors. This test may be done to predict
the risk for primary liver cancer (hepatocellular carcinoma). It is also done to
see how well therapy is working to treat certain cancers, such as hepatoma (a type
of liver cancer).
-
Antimitochondrial antibodies (AMAs).These antibodies in
the blood can mean primary biliary cirrhosis, chronic active hepatitis, or other
autoimmune disorders.
-
Serum alpha-1 antitrypsin test (A1AT). This test
measures the levels of alpha-1 antitrypsin in the blood. This test is done to help
find a rare form of emphysema in adults. And it is done to find a rare form of
liver disease (cirrhosis) in children and adults.
-
Viral hepatitis
tests. These check if you have or had hepatitis A, B, C, or D.
