To screen for, detect, evaluate, and monitor acute and chronic liver inflammation (hepatitis), liver infection, liver disease and/or and damage; to monitor side effects of certain medicines
Periodically to evaluate liver function; whenever you are at risk for liver injury; when you are taking medications that may affect your liver; when you have a liver disease; when you have symptoms associated with liver damage, such as jaundice
A blood sample drawn from a vein in your arm; for infants, a blood sample is often collected by pricking the heel and collecting a few drops of blood in a small tube (heelstick).
You may be instructed to fast overnight with only water permitted. Follow any instructions you are given. Inform the healthcare practitioner about all prescription and over-the-counter medications, herbal medications, vitamins and supplements you are taking as some medications/supplements affect the test results.
A liver panel is a group of tests that are performed together to detect, evaluate, and monitor liver disease or damage. The liver is a vital organ located in the upper right-hand part of the abdomen and behind the lower ribs. It takes up most of the space under the ribs and some space in the left upper abdomen as well.
The liver is responsible for several essential body functions, such as:
- Filtering and breaking down harmful substances from the blood to be removed from the body in urine and stools
- Making bile that helps digest food, especially fat
- Storing glycogen, which is used for energy
- Converting nutrients from the food we eat into essential blood components
- Regulating blood clotting
- Maintaining hormone balances
- Storing some vitamins
- Making factors that help the immune system fight infection
- Removing bacteria from the blood
In addition, liver cells convert ammonia (end product of amino acids) to a less harmful substance called urea, which the body can get rid of through the urine.
A variety of diseases and infections can cause acute or chronic damage to the liver, causing inflammation (hepatitis), scarring (cirrhosis), bile duct obstructions, liver tumors, and liver dysfunction. Alcohol, drugs, some herbal supplements, and toxins can also inure the liver. A significant amount of liver damage may occur before symptoms such as jaundice, dark urine, light-colored stools, itching (pruritus), nausea, fatigue, diarrhea, and unexplained weight loss or gain appear. Early detection of liver injury is essential in order to minimize damage and preserve liver function.
The liver panel typically consists of several tests that measure the following:
- 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 or damaged
- Aspartate aminotransferase (AST) – an enzyme found in the liver and a few other organs, particularly the heart and other muscles in the body
- 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
- 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.
Depending on your healthcare provider and the laboratory performing the testing, additional tests may be included in a liver panel. Examples include:
- Gamma-glutamyl transferase (GGT) – another enzyme found mainly in liver cells; it is a very sensitive marker for liver diseases, but it is not specific as it cannot differentiate between various causes of liver diseases. GGT is not recommended for routine use. It is used in conjunction with ALP to determine the source of increased ALP, either from bone or liver. High level of GGT can be found with alcohol consumption.
- 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-fetoprotein (AFP) – associated with regeneration or proliferation of liver cell and can be produced by certain types of tumors
- Autoimmune antibodies (e.g., ANA, SMA, anti-LKM-1) – associated with autoimmune liver diseases (autoimmune hepatitis (AIH) and primary biliary cirrhosis (PBC))
- How is the test used?
A liver panel may be used to:
- Screen for liver damage, especially if you have a condition or are taking medication that may affect your 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.
- Help diagnose liver disease if you have signs and symptoms that indicate possible liver dysfunction
- Monitor liver function if you have liver disease or a condition known to affect the liver, or to monitor the effectiveness of any treatments
One or more components of the liver panel may be used for monitoring. A series of bilirubin tests, for instance, may be ordered to evaluate and monitor a jaundiced newborn or a person with hemolytic anemia.
Abnormal results on a liver panel may prompt repeat testing of one or more of the tests, or of the whole panel, to see if the abnormal results persist. Additional testing may be needed to determine the cause of the liver dysfunction.
- When is it ordered?
A liver panel, or one or more of its components, may be ordered when you have increased risk for liver disease and/or dysfunction. You may be at increased risk if you:
- Take medications that may potentially damage the liver
- Are an alcoholic or heavy drinker
- Have a viral hepatitis or possible exposure to hepatitis viruses
- Have a family history of liver disease
- Are overweight, especially if you have diabetes and/or high blood pressure
A liver panel may be ordered when you have 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. Signs and symptoms may 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)
Often, a series of liver panels are 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.
- What does the test result mean?
Liver panel test results are not diagnostic of a specific condition. They indicate that there may be a problem with the liver. If you have no 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 there is a pattern. Your healthcare practitioner will evaluate the combination of liver test results to gain clues about the underlying condition. Often, further testing is necessary to determine the cause of the liver damage and/or disease.
The following table summarizes some combinations of results that may be seen in certain types of liver conditions or diseases.
Type of liver condition or disease 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 (8-50 times the upper reference limit); ALT is usually higher than AST Normal or only moderately increased (less than 3 times the upper limit) Normal Usually normal Chronic forms of various liver disorders Normal or increased Mildly or moderately increased; ALT is persistently increased Normal to slightly increased Normal Normal Alcoholic Hepatitis Normal or increased AST is moderately increased (less than 8 times the upper limit), 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 Normal or 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 Normal or decreased Usually prolonged Autoimmune Normal or increased Moderately increased; ALT usually higher than AST Normal or slightly increased Usually decreased Normal
If you take medications that may affect your liver, then abnormal test results may indicate a need to reevaluate the dose or choice of medication. When your liver disease is being monitored over time, then your 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 that liver function is stable or improving.
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 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 is often normal in liver disease but may be low due to decreased production, especially in liver cirrhosis.
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.
- What tests may be done in follow up to an abnormal liver panel to help determine the cause of liver injury?
In order to diagnose a liver disease, a healthcare practitioner will evaluate your liver panel test results and consider other factors such as signs, symptoms and clinical and family history. Depending on the results of the liver panel, a healthcare practitioner may suspect a particular cause of liver disorder and order follow-up lab tests and may order a liver biopsy and/or imaging scans to help confirm a diagnosis and determine the extent of liver damage.
Some examples additional lab tests include:
Suspected type of liver disorder Other or follow-up tests Viral hepatitis Acute viral hepatitis panel, hepatitis A testing, hepatitis B testing, hepatitis C testing Alcohol abuse/hepatitis GGT, Ethanol, carbohydrate-deficient transferrin Toxic or drug-induced Tests for toxins, drugs including drugs of abuse, acetaminophen Wilson disease Copper, Cerulosplasmin, eye exam, liver biopsy Alpha-1 antitrypsin deficiency Alpha-1 antitrypsin Autoimmune ANA, SMA, anti-LKM-1 Chronic Liver biopsy Liver cancer AFP, DCP
- Are these tests always performed together as a panel?
No. Each of these tests may be ordered individually. However, if your healthcare practitioner is interested in following two or more individual liver tests, your practitioner may order the entire liver panel because it offers more information. Alternatively, a healthcare provider may order individual tests when monitoring specific conditions.
- Why does my doctor want to know all of the medications and supplements I am taking?
Your healthcare provider will want to evaluate everything you are taking as a whole. Many over-the-counter drugs and herbal or dietary supplements have the potential to affect the liver. Excessive amounts of a drug, and/or a decreased ability to metabolize a drug, and/or a combination of drugs (including over-the-counter drugs and supplements) may injure the liver. For instance, taking too much acetaminophen and/or the combination taking acetaminophen and alcohol or other drugs (e.g., isoniazid and phenobarbital) can cause severe liver damage.
- Can I have liver disease if I feel fine?
Yes, early acute liver disease and chronic liver disease often cause 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, alpha 1- antitrypsin deficiency and Wilson disease, may be inherited and can progressively damage the liver. Early detection of these conditions allows them to be treated and managed appropriately.