A liver panel may be used to screen for liver damage, especially if someone has a condition or is taking a drug that may affect the liver. A comprehensive metabolic panel (CMP), which is often performed as part of a general health checkup, may be ordered instead of a liver panel for routine screening. This group of tests includes most of the liver panel as well as additional tests that evaluate other organs and systems within the body.

A liver panel or one or more of its component tests may be used to help diagnose liver disease if a person has signs and symptoms that indicate possible liver dysfunction. If a person has a known condition or liver disease, testing may be performed at intervals to monitor the health of the liver and to evaluate the effectiveness of any treatments. A series of bilirubin tests, for instance, may be ordered to evaluate and monitor a jaundiced newborn.

Abnormal tests on a liver panel may prompt a repeat analysis of one or more tests, or of the whole panel, to see if the elevations or decreases persist and/or may indicate the need for additional testing to determine the cause of the liver dysfunction.

The panel usually consists of several tests that are run at the same time on a blood sample. These typically include:

• Alanine aminotransferase (ALT) – an enzyme mainly found in the liver; the best test for detecting hepatitis
• Alkaline phosphatase (ALP) – an enzyme related to the bile ducts but also produced by the bones, intestines, and during pregnancy by the placenta (afterbirth); often increased when bile ducts are blocked.
• Aspartate aminotransferase (AST) – an enzyme found in the liver and a few other organs, particularly the heart and other muscles in the body
• Bilirubin – two different tests of bilirubin often used together (especially if a person has jaundice): total bilirubin measures all the bilirubin in the blood; direct bilirubin measures a form that is conjugated (combined with another compound) in the liver.
• Albumin – measures the main protein made by the liver; the level can be affected by liver and kidney function and by decreased production or increased loss.
• Total protein (TP) – measures albumin and all other proteins in blood, including antibodies made to help fight off infections

Depending on the healthcare provider and the laboratory, other tests that may be included in a liver panel are:

• Gamma-glutamyl transferase (GGT) – another enzyme found mainly in liver cells
• Lactate dehydrogenase (LD) – an enzyme released with cell damage; found in cells throughout the body
• Prothrombin time (PT) – the liver produces proteins involved in the clotting (coagulation) of blood; the PT measures clotting function and, if abnormal, may indicate liver damage.
• Alpha-feto protein (AFP) – associated with regeneration or proliferation of liver cell
• Autoimmune antibodies (e.g., ANA, SMA, anti-LKM-1) – associated with autoimmune hepatitis

A liver panel, or one or more of its components, may be ordered when someone is at risk for liver dysfunction. Some examples include:

• People who take medications that may potentially damage the liver
• Those who are alcoholics or heavy drinkers
• Those who have a history of known or possible exposure to hepatitis viruses
• Individuals whose families have a history of liver disease
• People who are overweight, especially if they have diabetes and/or high blood pressure

A liver panel may be ordered when a person has signs and symptoms of liver disease; however, most people who have liver disease do not have any of these symptoms until the disease has been present for many years or is very severe. Some of these include:

• Weakness, fatigue
• Loss of appetite
• Nausea, vomiting
• Abdominal swelling and/or pain
• Jaundice (yellowing of eyes or skin)
• Dark urine, light-colored stool
• Itching (pruritus)
• Diarrhea

Usually no one single set of liver tests is used to make a diagnosis. Often, several liver panels will be ordered over a few days or weeks to help determine the cause of the liver disorder and evaluate its severity.

When liver disease is detected, it may be monitored on a regular basis over time with the liver panel or with one or more of its components. A liver panel may also be ordered regularly to monitor the effectiveness of treatment for the liver disorder.

Liver panel test results are not diagnostic of a specific condition; they indicate that there may be a problem with the liver. In a person who does not have symptoms or identifiable risk factors, abnormal liver test results may indicate a temporary liver injury or reflect something that is happening elsewhere in the body – such as in the skeletal muscles, pancreas, or heart. It may also indicate early liver disease and the need for further testing and/or periodic monitoring.

Results of liver panels are usually evaluated together. Several sets of results from tests performed over a few days or weeks are often assessed together to determine if a pattern is present. Each person will have a unique set of test results that will typically change over time. A healthcare practitioner evaluates the combination of liver test results to gain clues about the underlying condition. Often, further testing is necessary to determine what is causing the liver damage and/or disease.

This table shows examples of some combinations of results that may be seen in certain types of liver conditions or diseases.

If a person is taking drugs that may affect their liver, then abnormal test results may indicate a need to reevaluate the dosage or choice of medication. When a person with liver disease is being monitored, then the healthcare practitioner will evaluate the results of the liver panel together to determine if liver function or damage is worsening or improving. For example, increasingly abnormal bilirubin, albumin, and/or PT may indicate a deterioration in liver function, while stable or improving results of these tests may indicate liver function preservation or improvement.

For individual tests:

Alanine aminotransferase (ALT)
A very high level of ALT is frequently seen with acute hepatitis. Moderate increases may be seen with chronic hepatitis. People with blocked bile ducts, cirrhosis, and liver cancer may have ALT concentrations that are only moderately elevated or close to normal.

Alkaline phosphatase (ALP)
ALP may be significantly increased with obstructed bile ducts, cirrhosis, liver cancer, and also with bone disease.

Aspartate aminotransferase (AST)
A very high level of AST is frequently seen with acute hepatitis. AST may be normal to moderately increased with chronic hepatitis. In people with blocked bile ducts, cirrhosis, and liver cancer, AST concentrations may be moderately increased or close to normal. When liver damage is due to alcohol, AST often increases much more than ALT (this is a pattern seen with few other liver diseases). AST is also increased after heart attacks and with muscle injury.

Bilirubin
Bilirubin is increased in the blood when too much is being produced, less is being removed, due to bile duct obstructions, or to problems with bilirubin processing. It is not uncommon to see high bilirubin levels in newborns, typically 1 to 3 days old.

Albumin
Albumin is often normal in liver disease but may be low due to decreased production.

Total protein (TP)
Total protein is typically normal with liver disease.

Gamma-glutamyl transferase (GGT)
A GGT test may be used to help determine the cause of an elevated ALP. Both ALP and GGT are elevated in bile duct and liver disease, but only ALP will be elevated in bone disease. Increased GGT levels are also seen with alcohol consumption and with conditions, such as congestive heart failure.

Lactate dehydrogenase (LD)
This is a non-specific marker of tissue damage. It is usually not elevated with most liver diseases, but it may be elevated with very acute liver disease or liver tumors. It is also elevated with a number of other conditions that do not affect the liver.

Prothrombin time (PT)
A prolonged or increased PT can be seen with liver disease, vitamin K deficiency, use of drugs to reduce risk of clotting (warfarin), and with coagulation factor deficiencies.

In order to diagnose a liver disease, a healthcare practitioner will evaluate the liver panel test results, order follow-up tests such as hepatitis virus testing, and may order a liver biopsy and/or imaging scans to help confirm a diagnosis and determine the extent of liver damage.