AST blood test: what the result means
Also known as: ASAT, GOT
0.13–0.55 µkat/l; laboratory intervals differ and are often given by sex
- Updated
- 2026-09-10
- Every number with its source
What AST is
Aspartate aminotransferase (AST, also called ASAT or GOT) takes part in the metabolism of amino acids and is present in many tissues — the liver, the heart muscle, skeletal muscle, the kidneys, the brain and red blood cells. That is why, unlike ALT, AST is not specific to the liver: it is raised by liver disease, by a heart attack, by muscle damage after an injury, intense exercise or seizures, and even by haemolysis of the blood in the sample. To assess liver disease, AST is always looked at together with ALT: when AST is higher than ALT, a doctor more often suspects alcoholic liver disease or advanced cirrhosis; when ALT is higher — fatty liver disease or viral hepatitis. A liver test panel consists of AST, ALT, GGT, alkaline phosphatase and bilirubin.
Reference range
| Group | Range, U/l | Source |
|---|---|---|
| Adults 0.13–0.55 µkat/l; laboratory intervals differ and are often given by sex | 8–33 | MedlinePlus Reviewed 2025-01-01 |
According to the MedlinePlus medical encyclopedia, the normal AST range for adults is 8–33 U/l (0.13–0.55 µkat/l). Laboratory intervals differ and are often given by sex, so compare your result with the range printed on your own result sheet. AST is always assessed together with ALT and, if needed, creatine kinase. If the figures on the sheet are unfamiliar, see how to read blood test results.
When AST is tested
- As part of a liver test panel — as a preventive check or when there are signs of liver disease
- When muscle damage or a muscle disease is suspected — together with creatine kinase
- To monitor the effect of medicines that can damage the liver
- After having had hepatitis, or when living with chronic liver disease — to follow how it develops
How to prepare
- No special preparation is needed
- It is worth avoiding intense physical exercise before the test — it raises AST because of the muscles
- Tell your doctor about medicines, supplements and alcohol
General points that apply to any blood sample are gathered in how to prepare for a blood test.
A raised AST
A raised AST can indicate liver damage (hepatitis, cirrhosis, fatty liver disease, alcohol, medicines), but also a heart attack, a muscle disease or injury, inflammation of the pancreas or mononucleosis. Intense exercise, burns, seizures and operations raise it temporarily. Pregnancy may also raise AST. That is why AST is always assessed together with ALT and, if needed, creatine kinase.
- Liver diseases — hepatitis, cirrhosis, fatty liver disease, impaired blood flow in the liver, tumours
- Alcohol and medicines that affect the liver
- A heart attack
- A muscle disease or injury, intense physical exercise
- Haemochromatosis
- Mononucleosis
- Inflammation of the pancreas
- Burns, seizures, operations — temporarily
What to discuss with a doctor
- ALT — the ratio of the two helps tell a liver cause from a muscle or a heart one
- Creatine kinase (CK), if muscle damage is suspected
- GGT, alkaline phosphatase, bilirubin — for the liver picture
- Alcohol, medicines, physical exercise before the test
- When to repeat the test
A low AST
A low AST is normal and does not indicate disease. Very low values are sometimes seen with a vitamin B6 deficiency or with kidney disease, but they usually have no clinical significance.
- A normal state
- Vitamin B6 deficiency — rarely
- Chronic kidney disease — rarely
Usually nothing needs to be done — a low AST is not a cause for concern.
Why AST and ALT are assessed together
ALT is found almost only in the liver, while AST is found elsewhere as well. When both are raised and ALT is higher, it is most often fatty liver disease or hepatitis; when AST is higher than ALT, a doctor more often suspects alcoholic liver disease or advanced cirrhosis. The ratio helps suggest the cause, but it does not confirm it.
What it costs in Lithuania
At the Medicina practica laboratory an AST test costs from €7 (September 2026 data). A family doctor can order liver tests free of charge when there are indications for it.
Full site in Lithuanian: proactiva.app
Frequently asked questions
›What is the normal AST range?
According to the MedlinePlus medical encyclopedia, the normal range is 8–33 U/l. Laboratory intervals differ and are often given separately for men and women — compare your result with your own result sheet.
›My AST is raised but my ALT is normal — what does that mean?
Such a combination more often points to a muscle or a heart cause rather than a liver one — intense exercise, muscle damage, less often a heart attack — or to haemolysis in the sample. A doctor usually also tests creatine kinase and repeats the test at rest.
›Does exercise raise AST?
Yes — AST is in the muscles, so intense exertion, especially strength training or a long run, raises it temporarily. It is worth avoiding intense physical exercise before the test.
›Why are AST and ALT assessed together?
ALT is found almost only in the liver, while AST is found elsewhere as well. When both are raised and ALT is higher, it is most often fatty liver disease or hepatitis; when AST is higher than ALT, a doctor more often suspects alcoholic liver disease or advanced cirrhosis. The ratio helps suggest the cause, but it does not confirm it.
›Do I need to fast before an AST test?
No, no special preparation is needed. What matters more is avoiding intense exercise and alcohol before the test, and telling your doctor about your medicines.
›How much does an AST test cost in Lithuania?
At the Medicina practica laboratory an AST test costs from €7 (September 2026 data). A family doctor can order liver tests free of charge when there are indications for it.
Sources
- MedlinePlus Medical Encyclopedia: AST blood test — 2026-09-06
- Medicina practica — 2026-09-06
Related markers
This site is not an emergency service. If severe chest or head pain, breathlessness, confusion, difficulty speaking, heavy bleeding or another acute problem has come on suddenly — do not wait for tests, call 112.
This information is not a diagnosis and does not replace a consultation with a doctor. Reference ranges depend on the laboratory, your age and sex — always compare your result with the range printed on your own report.