What It Measures
AST measures the level of the aspartate aminotransferase enzyme in your blood. This enzyme helps convert aspartate and alpha-ketoglutarate into oxaloacetate and glutamate as part of amino acid metabolism. Elevated levels indicate cellular damage in tissues where AST is concentrated, particularly the liver, heart, and skeletal muscles.
Aspartate aminotransferase (AST) is an enzyme found predominantly in the liver, heart, skeletal muscle, and kidneys. When these tissues are damaged, AST is released into the bloodstream, making it a key marker for detecting liver injury, muscle damage, and cardiac events. It is routinely measured as part of a comprehensive metabolic panel or liver function tests.
Current Value
What High Means
Elevated AST can indicate liver damage (hepatitis, cirrhosis, fatty liver disease, drug-induced liver injury), heart damage (myocardial infarction), skeletal muscle injury (rhabdomyolysis, intense exercise), hemolytic anemia, or bile duct obstruction. Very high levels (>10x normal) typically suggest acute hepatitis or toxic liver injury. Moderate elevations may reflect chronic liver disease, alcohol use, or medication side effects (statins, acetaminophen). AST is less specific to the liver than ALT, so the AST/ALT ratio helps differentiate causes — a ratio >2 suggests alcoholic liver disease.
Possible Symptoms
Fatigue, jaundice (yellowing of skin/eyes), dark urine, pale stools, nausea, vomiting, abdominal pain (especially upper right quadrant), loss of appetite, unexplained weight loss, swelling in legs or abdomen, easy bruising, itchy skin, muscle pain or weakness.
What Low Means
Low AST levels are generally not clinically concerning and are considered normal. However, very low levels may be associated with vitamin B6 deficiency (since B6 is a cofactor for AST), uremia, or chronic kidney disease. Some research suggests chronically low AST could reflect reduced metabolic activity or poor nutritional status.
Possible Symptoms
Low AST is typically asymptomatic. If related to vitamin B6 deficiency, symptoms may include fatigue, irritability, dermatitis, cracked lips (cheilosis), glossitis, confusion, and weakened immune function.
Risk Factors
Non-alcoholic fatty liver disease (NAFLD), alcoholic liver disease, viral hepatitis (A, B, C), drug-induced liver injury (acetaminophen, statins, NSAIDs), cirrhosis, hemochromatosis, Wilson's disease, autoimmune hepatitis, celiac disease, myocardial infarction, heart failure, rhabdomyolysis, hypothyroidism, obesity, metabolic syndrome, and type 2 diabetes.
Actionable Advice
Supplements
- •Milk Thistle (Silymarin)
- •N-Acetyl Cysteine (NAC)
- •Vitamin B6 (Pyridoxine)
- •Omega-3 Fatty Acids
- •Vitamin E (mixed tocopherols)
- •Alpha-Lipoic Acid
- •Turmeric/Curcumin
- •Phosphatidylcholine
- •Glutathione
- •Dandelion Root
Diet & Lifestyle
- •Limit alcohol consumption or abstain entirely
- •Maintain a healthy weight — even modest weight loss (5-10%) can significantly reduce liver enzymes
- •Follow a Mediterranean-style diet rich in vegetables, healthy fats, and lean protein
- •Exercise regularly (150+ min/week moderate activity) but allow recovery after intense sessions as exercise transiently raises AST
- •Avoid unnecessary medications and OTC drugs that stress the liver (especially acetaminophen in excess)
- •Stay hydrated to support liver detoxification
- •Minimize exposure to environmental toxins and chemicals
- •Get tested for hepatitis if you have risk factors
- •Manage blood sugar and insulin resistance through diet and exercise
- •Limit fructose and refined sugar intake to prevent fatty liver
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Historical Trend
Related Biomarkers
Resources & Studies
All Readings
| Date | Value | Change |
|---|---|---|
| 2026-01-28 | 22 U/L | -5.0 |
| 2025-08-25 | 27 U/L | +4.0 |
| 2025-06-27 | 23 U/L | — |