Aspartate Aminotransferase Test (AST) – Why am I having this test?
Aspartate aminotransferase test is used to diagnose or identify suspected liver diseases. This test is usually done when there are signs or symptoms of liver problems.
What is being tested?
This test measures the level of aspartate aminotransferase in your blood. AST is an enzyme that is released into the blood when liver cells or muscle cells are injured.
What kind of sample is taken?
A blood sample is required for this test. It is usually collected by inserting a needle into a blood vessel.
How do I prepare for this test?
Your health care provider may instruct you to avoid taking certain medicines for 12 hours before the test, particularly those that require an intramuscular (IM) injection. Follow your health care provider’s instructions.
How are the results reported?
Your test results will be reported as values. Your health care provider will compare your results to normal ranges that were established after testing a large group of healthy people (reference ranges). Reference ranges may vary among labs and hospitals. For this test, common reference ranges are:
- 0–5 days old: 35–140 units/L.
- Less than 3 years old: 15–60 units/L.
- 3–6 years old: 15–50 units/L.
- 6–12 years old: 10–50 units/L.
- 12–18 years old: 10–40 units/L.
- Adult: 0–35 units/L or 0–0.58 μkat/L (SI units).
What do the results mean?
Results that are higher than the reference ranges may indicate:
- Liver diseases.
- Skeletal muscle diseases.
- Other diseases that destroy the red blood cells or tissues of the pancreas.
Results that are lower than the reference ranges may indicate:
- Acute kidney disease.
- Pregnancy.
- Diabetic ketoacidosis.
- Chronic kidney dialysis.
- Symptomatic vitamin B1 deficiency.
Talk with your health care provider about what your results mean.
Questions to ask your health care provider
Ask your health care provider, or the department that is doing the test:
- When will my results be ready?
- How will I get my results?
- What are my treatment options?
- What other tests do I need?
- What are my next steps?
Summary
- Aspartate aminotransferase (AST) test is used to diagnose or identify suspected liver diseases. This test is usually done when there are signs or symptoms of liver problems.
- This test measures the level of aspartate aminotransferase in your blood. AST is an enzyme that is released into the blood when liver cells or muscle cells are injured.
- Your health care provider may instruct you to avoid taking certain medicines for 12 hours before the test, particularly those that require an intramuscular (IM) injection. Follow your health care provider’s instructions.
