Aspartate Transaminase

Does this test have other names?

AST, serum glutamic oxaloacetic transaminase test, SGOT 

What is this test?

This blood test is used to diagnose liver damage. Aspartate transaminase (AST) is an enzyme that is released when your liver or muscles are damaged. Although AST is found mainly in your liver and heart, AST can also be found in small amounts in other muscles. This test can also be used to monitor liver disease.   

Why do I need this test?

You may need this test if your healthcare provider suspects that your liver is damaged.

You might have this test if you have these symptoms related to liver disease:

• Dark-colored urine

• Light-colored stool

• Yellowing of the skin or eyes (jaundice)

• Nausea and vomiting

• Lack of appetite or weight loss

• Weakness or tiredness (fatigue)

• Itching (pruritus)

• Swelling in the belly, pain in the belly, or both

You may also have this test if you have a family history of liver illness or drink an abnormally large amount of alcohol. You may also have this test if you have a condition such as diabetes that may cause liver problems or if you take medicines that can cause liver damage.

What other tests might I have along with this test?

Your healthcare provider may also order the alanine aminotransferase (ALT) test. It's commonly used along with the AST test to look at your liver's function. ALT is an enzyme found in the liver. High levels of ALT can mean hepatitis. 

What do my test results mean?

Test results may vary depending on your age, gender, health history, the method used for the test, and other things. Your test results may not mean you have a problem. Ask your healthcare provider what your test results mean for you. 

Results are given in units per liter (units/L). Normal ranges for AST are:

• Males: 10 to 40 units/L

• Females: 9 to 32 units/L

Women tend to have slightly lower levels than men. Older adults tend to have slightly higher levels than the normal range for adults. 

If you have abnormally high levels of AST, you might have:

• Liver disease

• Muscle injury

• Heart attack

• Pancreatitis

Extremely high levels of AST may mean you have a disease like viral hepatitis, liver injury from medicines or toxins, or "shock liver." Shock liver is widespread liver damage caused by lack of oxygen or not enough blood supply. 

How is this test done?

The test is done with a blood sample. A needle is used to draw blood from a vein in your arm or hand. 

Does this test pose any risks?

Having a blood test with a needle carries some risks. These include bleeding, infection, bruising, and feeling lightheaded. When the needle pricks your arm or hand, you may feel a slight sting or pain. Afterward, the site may be sore. 

What might affect my test results?

Test results may be false-positive if you have diabetic ketoacidosis. They may also be false-positive if you take para-aminosalicylic acid or erythromycin estolate. These are antibiotics that treat bacterial infections.

How do I get ready for this test?

You don't need to prepare for this test.  Be sure your healthcare provider knows about all medicines, herbs, vitamins, and supplements you are taking. This includes medicines that don't need a prescription and any illicit drugs you may use.