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Liver Panel

Also known as:  Liver Function Tests, LFTs, Hepatic Function Panel

Formal name:  Hepatic Function Panel

Related tests:  ALT, ALP, AST, Bilirubin, Albumin, Total Protein, GGT, PT, LDH, CMP, Hepatitis A, Hepatitis B, Hepatitis C, Emergency and Overdose Drug Testing, Ethanol, ANA, ASMA,, Drugs of Abuse Testing, Copper, Ceruloplasmin 

At a Glance

Why get tested?

To screen for, detect, evaluate, and monitor for liver inflammation and damage.

When to get tested?

Periodically to evaluate liver function, whenever you are at risk for liver injury, when you have a liver disease, when you have symptoms such as jaundice.

Sample required?

A blood sample drawn from a vein in your arm.

The Test Sample

What is being tested? 

A liver panel is a group of tests that are performed together to detect, evaluate, and monitor liver disease or damage. The liver is one of the largest organs in the body and is located in the upper right-hand part of the abdomen and behind the lower ribs.  The liver metabolizes and detoxifies drugs and substances that are harmful to the body.  It produces blood clotting factors, proteins, and enzymes, helps maintain hormone balances, and stores vitamins and minerals.  Bile, a fluid produced by the liver, is transported through ducts directly to the small intestine to help digest fats or to the gallbladder to be stored and concentrated for later use. 

A variety of diseases and infections can cause acute or chronic damage to the liver, causing inflammation, scarring, bile duct obstructions, clotting abnormalities, and liver dysfunction.  Alcohol, drugs, some herbal supplements, and toxins can also pose a threat.  A significant amount of liver damage may be present before symptoms such as jaundice, dark urine, light-colored stools, pruritus, nausea, fatigue, diarrhea, and unexplained weight loss or gain emerge.  Early detection is essential in order to minimize damage and preserve liver function.

The liver panel measures enzymes, proteins, and substances that are produced or excreted by the liver and are affected by liver injury.  Some are released by damaged liver cells and some reflect a decrease in the liver’s ability to perform one or more of its functions.  When performed together, these tests give the doctor a snapshot of the health of the liver, an indication of the potential severity of any liver injury, change in liver status over time, and a starting place for further diagnostic testing.

The panel usually consists of several tests that are run at the same time on a blood sample. These may 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; often increased when they are blocked

• Aspartate aminotransferase (AST) – an enzyme found in the liver and a few other places, particularly the heart and other muscles in the body

• Bilirubin (total and direct) – two different tests of bilirubin are often used together, especially if a person has jaundice: total bilirubin measures all of 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 and tells whether or not the liver is making an adequate amount of this protein

• Total protein - measures albumin and all other proteins in blood, including antibodies made to help fight off infections

Depending on the doctor 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 (LDH)

• 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. 

How is the sample collected for testing? 

A blood sample is obtained by inserting a needle into a vein in the arm.

Is any test preparation needed to ensure the quality of the sample?

Some of the tests that may be included in the panel require fasting, so you may be instructed to fast overnight with only water permitted. Follow any instructions you are given.

The Test

How is it used?

A liver panel may be used to screen a person for liver damage, especially someone who has a condition, or is taking a drug, that may affect the liver. A comprehensive metabolic panel (CMP) 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 detect liver disease if a person has symptoms that indicate possible liver dysfunction or if a person is being monitored or treated for a known condition or liver disease.  A bilirubin test, for instance, may be ordered to evaluate and monitor a jaundiced newborn.

Abnormal tests on a liver panel may prompt a repeat analysis to see if the elevation or decrease persists and/or may indicate the need for additional testing to determine the cause of the liver dysfunction.

The group of tests may also be ordered to monitor liver function and the effectiveness of treatment in someone who has a liver disease.

When is it ordered?

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

• Persons with a history of known or possible exposure to hepatitis viruses 

• Heavy alcohol drinkers 

• Family history of liver disease 

• Persons who take drugs that might occasionally damage the liver

A liver panel may be ordered when a person has signs and symptoms of liver disease:

• Weakness, fatigue

• Loss of appetite

• Nausea, vomiting

• Abdominal swelling and/or pain

• Jaundice

• Dark urine, light colored stool

• Itching (pruritis)

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

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. 

What do the test results mean?

The 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 which will typically change over time. A doctor 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:

Liver Problem	Bilirubin	ALT and AST	ALP	Albumin	PT
Acute liver damage (due, for example,  to  infection, toxins or drugs, etc)	Normal or increased usually after ALT and AST are already increased	Usually greatly increased; ALT is usually higher than AST	Normal or only moderately increased	Normal	Usually normal
Chronic forms of various liver disorders	Normal or increased	Moderately increased	Normal to slightly increased	Normal	Normal
Alcoholic Hepatitis	Normal or increased	AST is usually at least  twice the level of ALT	Normal or  moderately increased	Normal	Normal
Cirrhosis	May be increased but this usually occurs later in the disease	AST is usually higher than ALT but levels are usually lower than in alcoholic disease	Normal or increased	Usually decreased	Usually prolonged
Bile duct obstruction, cholestasis	Normal or increased; increased in complete obstruction	Normal to moderately increased	Increased; often greater than 4 times what is normal	Usually normal but if the disease is chronic, levels may decrease	Usually normal
Cancer that has spread to the liver (metastasized)	Usually normal	Normal or slightly increased	Usually greatly increased	Normal	Normal
Cancer originating in the liver (hepatocellular carcinoma, HCC)	May be increased especially if the disease has progressed	AST higher than ALT but levels lower than that seen in alcoholic disease	Normal or increased	Usually decreased	Usually prolonged
Autoimmune	Normal or increased	Moderately increased	Normal or slightly increased	Normal or decreased	Normal

If a person is taking drugs that may affect their liver then abnormal test results may indicate a need to re-evaluate the dosage or choice of medication.  When a person with liver disease is being monitored, then the doctor will evaluate the results of the liver panel together to determine if liver function in 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, 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 sometimes be low due to decreased production.

Total Protein

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 (LDH)

This is a non-specific marker of tissue damage.  It may be elevated with liver disease but also with a number of other conditions.

Prothrombin Time (PT)

A prolonged or increased PT can be seen with liver disease, vitamin K deficiency and with coagulation factor deficiencies.

Is there anything else I should know?

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

Common Questions

Why does my doctor want to know all of the medications I am taking?

Many over-the-counter drugs and herbal or dietary supplements have the potential to affect the liver. Excessive acetaminophen use and the combination of acetaminophen and alcohol for instance can cause severe liver damage, as can exposure to toxins such as poisonous mushrooms.

Can I have liver disease if I feel fine?

Yes, early liver disease often causes no symptoms or mild nonspecific symptoms, such as fatigue and nausea.

Can I have abnormal test results and not have liver disease?

Yes, many temporary conditions, such as shock, burns, severe infections, muscle trauma, dehydration, pancreatitis, hemolysis, and pregnancy can cause one or more of the liver function tests to be abnormal.

Why is my family history important?

Some liver conditions, such as hemochromatosis and Wilson’s disease may be inherited. Early detection of these conditions allows them to be treated and managed appropriately.

What tests can be done in follow up to an abnormal liver panel to help determine the cause of liver injury?

Depending on the results of the liver panel and other factors such as signs, symptoms and clinical and family history, a doctor may suspect a particular cause of liver disorder and order follow up tests. Examples include:

Suspected Liver Problem	Other or Follow-Up Tests
Viral infection	Hepatitis A, B or C
Alcohol abuse/hepatitis	GGT, ethanol
Toxic or drug induced	Tests for toxins, drugs including drugs of abuse
Wilson disease	Copper, cerulosplasmin
Autoimmune	ANA, ASMA
Chronic	Liver biopsy
Liver cancer	AFP, DCP

Content last reviewed in June 2011. | This page was last modified in July 2011.