A glutamic-oxaloacetic transaminase (SGOT) or aspartate aminotransferase (AST) test measures the levels of the enzyme AST in the blood to assess liver health. Numbers over 50 for cisgender males and 45 for cisgender females indicate potential liver damage.
The SGOT test is a blood test that’s part of a liver profile. It measures one of two liver enzymes called serum glutamic-oxaloacetic transaminase.
This enzyme is now usually called AST, which stands for aspartate aminotransferase. An SGOT test (or AST test) evaluates how much of the liver enzyme is in the blood.
A SGOT test may be used to help your doctor diagnose liver damage or liver disease. When liver cells are damaged, SGOT leaks into the blood stream, raising your blood’s level of this enzyme.
The test may be used to evaluate liver health for people who are already known to have conditions that affect their liver, such as hepatitis C.
SGOT is found in several areas of your body, including your kidneys, muscles, heart, and brain. If any of these areas are damaged, your SGOT levels may be higher than normal. For example, the levels could be raised during a heart attack or if you’ve had a muscle injury.
Because SGOT appears throughout your body, part of the liver profile also includes an ALT test. ALT is the other essential liver enzyme. Unlike SGOT, it’s found in heaviest concentrations in the liver. An ALT test is often a more definitive indicator of potential liver damage.
The SGOT test is a simple blood test. It can technically be done without any special preparation. Still, there are a couple steps you can take to make the process easier.
Avoid taking any over-the-counter (OTC) medications, including acetaminophen (Tylenol), in the two days before your test. If you do take them, remember to tell your doctor. You should tell your doctor about all the medications you’re taking before they administer the test so that they can account for them when reading the results.
Drink plenty of water the night before your test, too. Staying hydrated will make it easier for your technician to draw your blood. Make sure you wear something that allows your forearm — preferably up to the elbow — to be easily accessible for the technician to draw blood from.
The technician will call you back and have you sit down in a chair. They’ll tie an elastic band tightly around your arm and search for a good vein to use. Then they’ll clean the area before using a needle to draw blood from the vein.
It will only take them a minute to draw the blood into a small vial. After, they’ll apply gauze to the area for a moment, remove the elastic band, and place a bandage on top. You’ll be set to go.
You may have a small bruise for up to a week. Relaxing during the procedure as much as possible will prevent your muscles from tensing, which can cause pain during a blood draw.
The blood sample will later be processed by a machine. While it only takes a few hours to process the sample, it may take several days to get the results from your doctor.
There are very few risks to having an SGOT test. Make sure you’re well hydrated the night before to help prevent episodes of feeling light-headed or faint. If you feel light-headed or faint following the procedure, let the technicians know. They’ll let you stay sitting and may bring you water until you feel well enough to get up and go.
If the results of your SGOT test are high, that means one of the organs or muscles containing the enzyme could be damaged. These include your liver, but also the muscles, heart, brain, and kidneys. Your doctor may order follow-up tests to rule out another diagnosis.
The normal range of an SGOT test is generally between 8 and 45 units per liter of serum. In general, cisgender males may naturally have higher amounts of AST in the blood. A score above 50 for cisgender males and 45 for cisgender females is high and may indicate damage.
There may be some variation in the normal ranges depending on the technique the lab used. The exact range of the lab will be listed in the report of the results.
Extremely high levels of AST or ALT indicate conditions that cause severe liver damage. These conditions include:
If your SGOT test is inconclusive, your doctor may order additional follow-up tests. If they’re looking at your liver function or checking for liver damage in particular, they may also order the following:
- Coagulation panel: This measures your blood’s ability to clot and evaluates the function of clotting-factor proteins produced in the liver.
- Bilirubin test: Bilirubin is a molecule and by-product of the routine destruction of red blood cells, which occurs in the liver. It’s typically released as bile.
- Glucose tests: A liver that isn’t functioning correctly may lead to unusually low glucose levels.
- Platelet count: Low platelet levels may indicate liver disease.
All of these tests are blood tests and can be completed in a complete blood panel test (CBP). If other organs or muscles are thought to be the reason for your high AST levels, your doctor may order additional testing to diagnose the problem, such as an ultrasound of the liver.