An AST blood test helps determine how well the liver is functioning by measuring levels of aspartate aminotransferase (AST) in the blood. Too much of this enzyme can indicate a problem, such as liver damage. Another name for the test is a serum glutamic-oxaloacetic transaminase (SGOT) test.
Aspartate aminotransferase (AST) is an enzyme mostly found in the liver. AST is also present in other parts of the body, including the:
- kidneys
- heart
- muscles
Another name for the AST enzyme is serum glutamic-oxaloacetic transaminase (SGOT).
Most people have low levels of the AST enzyme. Damage to liver cells can cause the release of extra AST into the blood though, leading to higher levels of the enzyme.
After taking a blood test, doctors will classify AST ranges as normal, high, or low. Laboratories may use different testing methods for analyzing samples, so normal ranges can vary between each laboratory.
There is not an exact range for AST levels, as levels can vary among people and still be normal. AST levels can vary depending on factors such as:
- age
- sex
- weight
- race
The measurements for AST levels are typically in units per liter (U/L) or international units per liter (IU/L). On a test result, the laboratory will usually list their specific reference range.
People will need to look at this reference range and discuss with their doctor what their test results mean for them. To understand the results of an AST blood test, a doctor will also look at other enzymes that can indicate a liver problem.
The following table indicates general AST blood test ranges. However, reference ranges can vary slightly among different laboratories.
| Adults | Children | |
|---|---|---|
| Normal | <36 U/L | 10–40 IU/L |
| High | >36 U/L >1,000 U/L are very high levels and may be a sign of liver injury or hepatitis | >40 IU/L which may be a sign of liver inflammation |
Results from an AST blood test can help indicate liver health.
If AST levels are high, it may also be a sign of:
- chronic hepatitis
- damage from alcohol
- cholestasis, a decrease in bile flow
- heart, kidney, bone, or muscle damage
- liver cancers
- liver scarring, known as liver cirrhosis
Very high AST levels are usually a sign of progressing liver damage, often due to acute hepatitis.
Low AST levels may indicate:
- vitamin B6 deficiency
- kidney disease
- liver disease
- cirrhosis
- cancer
- autoimmune conditions
- genetic conditions
A doctor may also test levels of alanine aminotransferase (ALT), another liver enzyme. ALT levels occur in higher concentrations in the liver.
If ALT levels are normal but AST levels are high, it could indicate a health problem outside of the liver, or it may be a sign of alcohol-induced liver damage.
Having high levels of AST and no other signs of a problem is not necessarily a cause for concern. People with normal liver function can have high AST levels, which may be due to:
- age
- sex
- race
- certain medications
A person should always discuss any medications or health products they take with a doctor.
Doctors primarily use the AST blood test to check for and assess liver problems, usually alongside other liver tests. The AST protein mainly occurs in the liver and heart. With liver damage, AST can leak from the liver into the bloodstream. When this happens, AST levels in the blood will be higher than normal.
AST also occurs in the brain, heart, kidneys, and muscles. If there is damage in any of these areas, AST levels may also increase.
To rule out issues affecting areas outside the liver, doctors may order a check of the second liver enzyme, ALT, at the same time. If both levels are high, it may indicate a problem with a person’s liver. If only AST levels are high, this may indicate a problem with another organ or system.
People may have an AST test for screening, diagnosis, or monitoring purposes. A doctor may recommend this test if a person:
- has risk factors for liver disease, such as family history, obesity, or diabetes
- has symptoms of a liver problem, such as jaundice, fatigue, or unexplained weight loss
- is undergoing treatment for a liver condition, as an AST blood test can help show how well treatment is working
Alanine aminotransferase (ALT) is an enzyme that mostly occurs in the liver. If there is damage to liver cells, ALT levels in the bloodstream can increase. An ALT test can help indicate liver health, along with other liver enzyme tests.
Healthcare professionals may use both ALT and AST tests to check for the presence of liver enzymes in the blood, as this can give them a clearer idea of overall liver function and health.
Learn more about the ALT test here.
The AST blood test is straightforward and similar to any other blood test. A healthcare professional may take the following steps:
- sit the person down and tie a stretchy band around the upper arm to increase blood flow to that area
- clean the site of the blood draw with an antiseptic wipe
- insert a needle into a vein in the arm to take a blood sample, which may cause people to feel a mild prick or pain
- remove the needle once they have drawn enough blood
- send the blood sample to a laboratory for testing
An AST blood test will usually only take a few minutes in total.
In some cases, people may be able to take an AST test at home. Using an at-home test kit, people will take a blood sample from their fingertip and send the sample to a laboratory. People may receive AST blood test results through the mail, an app, or an online system.
Learn how long it might take to receive blood test results here.
Preparation
People may need to fast for several hours if they are having a combination of liver enzyme tests.
If people are only having an AST blood test, they may not need to fast or prepare in any way.
People will need to let their doctor know if they are taking any medications or supplements, as some may interfere with liver enzyme levels.
As a healthcare professional will be taking blood from the arm, it may be helpful to wear short sleeves during the test.
(Video) ALT, AST, ALP & GGT (Liver Function Tests) - How to Interpret
As with any blood test, an AST blood test has very few risks. It is rare to experience any severe side effects, but people may have some mild bruising or discomfort in the area at the site of the blood draw.
A healthcare professional will place a Band-Aid or bandage on the arm to stop any bleeding.
People may want to have something to eat after the test, particularly if they were fasting beforehand. It is safe for people to drive and continue their usual activities after an AST blood test, unless they experience any unusual symptoms.
A doctor may order tests along with an AST blood test or follow-up tests. This is to help ensure proper diagnosis and determine the best course of treatment. These tests
- ALT test: A doctor may order an ALT test alongside an AST test.
- Platelet count: Low platelet levels may indicate HELLP syndrome during pregnancy.
- Coagulation panel: This measures the functioning of clotting-related proteins that the liver produces.
- Complete metabolic panel: This assesses how well the kidneys and liver are working and shows levels of electrolytes.
- Bilirubin test: A bilirubin test checks levels of a byproduct created when the liver breaks down red blood cells.
- Glucose test: High or low blood glucose levels may indicate a liver problem.
- Viral testing: This can help doctors check for hepatitis.
- Imaging: A doctor may order images of the liver via ultrasound.
The extent of follow-up testing will depend on a person’s results. A doctor may also take additional blood tests, imaging tests, or a biopsy to identify or rule out any potential conditions relating to abnormal AST levels.
Learn about different types of blood tests here.
An AST blood test, or SGOT test, checks how much AST, a liver enzyme, is present in the blood. High levels of AST in the bloodstream could be a sign of liver damage, or cell damage in another organ such as the heart or kidneys.
Doctors may also take additional tests to check other liver enzymes, such as ALT, to get more information on the health of the liver.
FAQs
What is an alarming AST level? ›
An AST/ALT ratio higher than one (where the AST is higher than ALT) means you may have cirrhosis. An AST/ALT ratio higher than 2:1 (where the AST is more than twice as high as the ALT) is a sign of alcoholic liver disease.
When should I be concerned about SGOT AST? ›The normal range of an SGOT test is generally between 8 and 45 units per liter of serum. In general, men may naturally have higher amounts of AST in the blood. A score above 50 for men and 45 for women is high and may indicate damage.
Is it better to have high or low AST? ›Normally, AST levels in your blood are low. When your liver is damaged, it puts more AST into your blood, and your levels rise. A high AST level is a sign of liver damage, but it can also mean you have damage to another organ that makes it, like your heart or kidneys.
What level of AST indicates liver damage? ›A normal AST:ALT ratio should be <1. In patients with alcoholic liver disease, the AST:ALT ratio is >1 in 92% of patients, and >2 in 70%. AST:ALT scores >2 are, therefore, strongly suggestive of alcoholic liver disease and scores <1 more suggestive of NAFLD/NASH.
Are low AST levels good? ›Low AST levels are expected and normal – they are just uncommon in the general population. The reference ranges are based on where 95% of the healthy population falls into, which means that there are 5% of the people who are healthy and not within the reference range!
What is a good number for AST? ›Normal Results
The normal range is 8 to 33 U/L. Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or may test different samples.
An SGOT/SGPT ratio greater than 2 is highly suggestive of alcoholic hepatitis and cirrhosis.
Should I be concerned if my AST SGOT is high? ›High levels of AST in the blood may be a sign of hepatitis, cirrhosis, mononucleosis, or other liver diseases. High AST levels may also be a sign of heart problems or pancreatitis. If your results are not in the normal range, it doesn't always mean that you have a medical condition that needs treatment.
How do you fix a high AST SGOT? ›- Restrict alcoholic beverages. Alcohol consumption can be harmful to the liver.
- Quit smoking as well as avoid passive smoking.
- Exercise regularly. Simple exercises such as jogging, brisk walking, and swimming can help prevent obesity, a risk factor for liver diseases.
- Avoid exposure to harmful chemicals.
Very high AST levels are usually a sign of progressing liver damage, often due to acute hepatitis. Low AST levels may indicate: vitamin B6 deficiency. kidney disease.
Does high AST mean liver damage? ›
Aspartate transaminase (AST).
Like ALT, AST is normally present in blood at low levels. An increase in AST levels may indicate liver damage, disease or muscle damage.
AST levels can fluctuate between 5 and 10% from one day to the next in the same individual. Moderate exercise increases AST levels for as long as 24 hours, usually less than 3 times the upper limit of normal.
What are the 4 warning signs of a damaged liver? ›yellowing of the skin or whites of the eyes (jaundice) swelling in the legs, ankles and feet caused by a build-up of fluid (oedema) swelling in your abdomen caused by a build-up of fluid known as ascites. a high temperature and shivering attacks.
What organ is affected by AST? ›Aspartate transferase (AST), also known as aspartate aminotransferase, is an enzyme that exists in your liver, heart, brain, pancreas, kidneys, muscles and many tissues in your body. Although it can be found throughout your body, AST is most commonly associated with liver health.
What number is too high for AST? ›Typically the range for normal AST is reported between 10 to 40 units per liter and ALT between 7 to 56 units per liter. Mild elevations are generally considered to be 2-3 times higher than the normal range. In some conditions, these enzymes can be severely elevated, in the 1000s range.
What is normal AST levels for females? ›Normal ranges for AST are: Men: 14 to 20 units/L. Women: 10 to 36 units/L.
What level of ALT is concerning? ›An ALT test result of >100 IU/l is a clear indicator of serious liver disease, but a mildly elevated ALT result (30–100 IU/l) is often ascribed to the use of medication (for example statins) or alcohol, obesity, or, for lower ALT levels (<50 IU/l), considered as part of the normal distribution of test results.
Which is worse high AST or ALT? ›Increased ALT activity is more specific for liver damage than increased aspartate aminotransferase (AST) activity.
Does high SGOT mean fatty liver? ›SGPT and SGOT are certain enzymes that are produced by the liver and its cells. Elevated SGPT and SGOT levels are an indication of liver cell injury or damage and hence they should be detected through regular health check-ups. There are a few lifestyle habits that can keep your liver and body in a healthier state.
What are the symptoms of high SGOT? ›...
They are as follows:
- Jaundice.
- Easy bruising.
- Excessive bleeding.
- Shortness in breath.
- Swelling in the leg area.
- Fatigue.
- Weakness.
- Nausea and vomiting.
Is High SGOT reversible? ›
Fatty liver disease can, in some cases, be reversed with lifestyle changes and medical treatment. The treatment plan will depend on the type and severity of the fatty liver disease.
Does high AST mean fatty liver? ›Laboratory abnormalities often are the only sign of non-alcoholic fatty liver disease. The most common abnormal laboratory test results are elevated alanine transaminase (ALT) and aspartate transaminase (AST), usually one to four times the upper limits of normal.
What causes abnormal AST levels? ›- Scarring of the liver (cirrhosis)
- Death of liver tissue.
- Heart attack.
- Too much iron in the body (hemochromatosis)
- Swollen and inflamed liver (hepatitis)
- Lack of blood flow to the liver (liver ischemia)
- Liver cancer or tumor.
What is the SGPT & SGOT. SGPT and SGOT are blood tests that indicate the status of your liver. If you have elevated levels of these two enzymes, your doctor may conduct further testing to determine if you have liver disease. This test can also be used to monitor the progress of treatment for liver disease.
How long does it take for AST levels to go down? ›Elevated levels caused by these factors will generally return to normal in about 2 to 4 weeks without treatment.
What is the normal level of SGOT? ›The normal level of SGOT is 5 to 40 units per litre of blood serum. The enzyme gets released into the bloodstream when there is liver damage, disease, or muscle damage.
What numbers indicate fatty liver? ›Fatty liver disease (steatosis) is a common condition caused by having too much fat build up in your liver. A healthy liver contains a small amount of fat. It becomes a problem when fat reaches 5% to 10% of your liver's weight.
Does AST decrease with age? ›Conclusion: With advancing age, ALT levels progressively declined while AST levels remained stable, leading to a higher AAR. Although higher AAR is often used as a surrogate measure of advanced fibrosis, advancing age can also contribute to increased AAR.
How long does AST stay elevated? ›ALT and AST can remain elevated for 7 or more days after strenuous exercise.
Can high AST levels be temporary? ›Elevated liver enzymes have a variety of causes, including liver disease and medication. Elevated liver enzymes may also be temporary. If your blood test shows high levels of liver enzymes, talk with your provider. They'll work to figure out the cause.
How do you feel when your liver fails? ›
Nausea. Vomiting. A general sense of feeling unwell (malaise) Disorientation or confusion.
What is the first stage of liver damage? ›Stage 1: Inflammation
In the early stages of liver disease, the liver will become swollen or inflamed as the body's natural response to injury. Liver inflammation, or hepatitis, can also occur when there are more toxins in the blood than the liver is able to manage.
Liver failure occurs when your liver isn't working well enough to perform its functions (for example, manufacturing bile and ridding your body of harmful substances). Symptoms include nausea, loss of appetite, and blood in the stool. Treatments include avoiding alcohol and avoiding certain foods.
Is AST related to heart? ›AST is normally found in red blood cells, liver, heart, muscle tissue, pancreas, and kidneys. AST formerly was called serum glutamic oxaloacetic transaminase (SGOT). Low levels of AST are normally found in the blood.
What disease is AST? ›AST (SGOT) Hepatitis C for Patients
It is also known as serum glutamic-oxaloacetic transaminase, or SGOT. AST is a protein made by liver cells. When liver cells are damaged, AST leaks out into the bloodstream and the level of AST in the blood becomes elevated.
Test Overview
An aspartate aminotransferase (AST) test measures the amount of this enzyme in the blood. AST is normally found in red blood cells, liver, heart, muscle tissue, pancreas, and kidneys. AST formerly was called serum glutamic oxaloacetic transaminase (SGOT). Low levels of AST are normally found in the blood.
An enzyme found in the liver, heart, and other tissues. A high level of SGOT released into the blood may be a sign of liver or heart damage, cancer, or other diseases. Also called aspartate transaminase and serum glutamic-oxaloacetic transaminase.
Is 300 AST high? ›If the AST level is less than 300 U/L, a ratio of AST to ALT of more than 2 suggests alcohol-associated liver disease, and a ratio of more than 3 is highly suggestive of alcohol-associated liver disease.
What is considered extremely high AST and ALT? ›Severe ALT and AST elevations (ALT and AST greater than 15 times the ULN) suggest severe acute liver cell injury: acute viral hepatitis, ischemic hepatitis or other vascular disorder, toxin-mediated hepatitis, acute autoimmune hepatitis.
Is 200 AST high? ›The AST is typically in the 100 to 200 IU/L range, even in severe disease, and the ALT level may be normal, even in severe cases. The AST level is higher than the ALT level, and the ratio is greater than 2:1 in 70% of patients. A ratio greater than 3 is strongly indicative of alcoholic hepatitis.
What is considered very high ast alt? ›
Although levels of ALT and AST can be extremely elevated (exceeding 2,000 U per L in cases of hepatocyte injury and necrosis related to drugs, toxins, ischemia, and hepatitis), elevations less than five times the upper limit of normal (i.e., about 250 U per L and below) are much more common in primary care medicine.
Does high AST mean liver failure? ›High levels of AST in the blood may be a sign of hepatitis, cirrhosis, mononucleosis, or other liver diseases. High AST levels may also be a sign of heart problems or pancreatitis. If your results are not in the normal range, it doesn't always mean that you have a medical condition that needs treatment.
What level of AST is fatty liver? ›However, patients with nonalcoholic fatty liver disease may have normal transaminase levels. The ratio of AST/ALT usually is less than 1 (in alcoholic liver disease, this ratio typically will be greater than 2) but may increase as the severity of the liver damage increases.
What is worse high AST or ALT? ›Increased ALT activity is more specific for liver damage than increased aspartate aminotransferase (AST) activity.
What causes elevated AST? ›Chronic alcohol consumption, drugs, non-alcoholic steatohepatitis (NASH) and chronic viral hepatitis are common causes associated with raised ALT and AST. In chronic viral hepatitis, the elevation of liver enzyme may not correlate well with the degree of liver damage.
How long does it take for AST and ALT to return to normal? ›Sometimes, factors such as hormonal changes or reactions to medications can cause temporarily elevated liver enzyme levels. Elevated levels caused by these factors will generally return to normal in about 2 to 4 weeks without treatment.
Can exercise cause high AST levels? ›ALT and AST can remain elevated for 7 or more days after strenuous exercise. The higher the intensity and the longer the duration of workout will result in higher peak levels and levels remaining high for longer. Untrained athletes will see larger and longer increases relative to more trained athletes..
How do you lower AST levels in your liver? ›- Drinking coffee. Drinking coffee can help to lower ALT levels. ...
- Exercising regularly. ...
- Losing excess weight. ...
- Increasing folic acid intake. ...
- Making dietary changes. ...
- Reducing high cholesterol. ...
- Taking care with medications or supplements. ...
- Avoiding alcohol, smoking, and environmental toxins.
ALT levels greater than 15 times the normal range indicate severe acute liver cell injury and evaluation should be initiated immediately. The differential diagnosis for patients with severe acute liver injury (ALT levels >15 times the normal range) is relatively limited.
What medications can cause liver enzymes to be elevated? ›- The antibiotics synthetic penicillin, ciprofloxacin and tetracycline.
- The anti-seizure drugs carbamazepine and phenytoin and valproic acid.
- Nonsteroidal anti-inflammatory drugs (NSAIDs)
- The diabetes drugs sulfonylureas and glipizide.
- The tuberculosis drugs isoniazid, pyrazinamide and rifampin.
Can dehydration cause elevated liver enzymes? ›
In conclusion, hepatic enzymes can be temporary elevated in patients with uncomplicated acute AGE with severe dehydration.