What do my ALT and AST results mean?

For evidence-based information about ALT and AST (Liver Enzymes) Test, visit this page.

What might be causing the elevation?

For evidence-based information about ALT and AST (Liver Enzymes) Test, visit this page.

Do I need additional liver tests or imaging?

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What factors may be affecting my results?

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How often should I be retested?

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Home → Tests → ALT and AST

ALT and AST (Liver Enzymes) Test

⚠️ Update approaching🔬 Evidence: StrongInternal Medicine

Diğer adları: Alanine aminotransferase, Liver enzymes, Liver function test

⚠️

Discuss your test results with your doctor. This page is for informational purposes only and does not provide a diagnosis.

⚡ Key Facts

• ALT and AST are commonly used blood markers for evaluating liver cell damage • ALT is more specific to the liver; AST is also found in heart, muscle, and other tissues • The degree and pattern of elevation provide diagnostic clues • Should be interpreted alongside other liver tests

🧪 What Does This Test Measure?

ALT and AST are enzymes released into the blood when liver cells or other tissues are damaged, with ALT being more specific to the liver.

📋 Why Is It Ordered?

Ordered for liver disease evaluation, medication monitoring, and metabolic dysfunction-associated liver disease assessment.

🔧 Preparation

Fasting is generally not required. Heavy alcohol consumption and intense exercise before testing may temporarily elevate levels.

📊 Reference Ranges

ALT: Men 7–56 IU/L, Women 7–45 IU/L AST: Men 10–40 IU/L, Women 9–32 IU/L ⚠️ Reference ranges vary by laboratory.

⬆️ High Values

Elevated ALT and AST may be associated with fatty liver disease, viral hepatitis, alcohol use, medications, or muscle damage (particularly AST).

⬇️ Low Values

Low ALT and AST are generally not clinically significant. Rarely, very low levels may be associated with vitamin B6 deficiency or advanced liver disease.

⚙️ What Can Affect Results?

Age, sex, body weight, physical activity, alcohol, medications, and laboratory method may affect ALT and AST results.

🔬 Evidence Summary

Strong evidence: 2 guidelines, 1 systematic review, 1 meta-analysis, and 2 reviews.

📚 Most Important Studies on This Topic

ACG Clinical Guideline: Evaluation of Abnormal Liver Chemistries

Guideline· American Journal of Gastroenterology · 2017 · PMID: 27995906

EASL-EASD-EASO Clinical Practice Guidelines on the Management of Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD)

Guideline· Journal of Hepatology · 2024 · PMID: 38851997

Evaluation of Abnormal Liver-Enzyme Results in Asymptomatic Patients

Review· New England Journal of Medicine · 2000 · PMID: 10781624

✅ Key Takeaways

💡

What you learned: ALT and AST indicate liver cell damage. ALT is more liver-specific; the pattern and degree of elevation guide further evaluation.

⛔

Elevated ALT or AST alone cannot diagnose a specific liver disease. Additional tests and clinical context are needed.

🔬 Sources Used on This Page

6 sources · Most recent publication: 2024

📋

Guideline

Expert society and guideline recommendations

sources

📊

Systematic review / meta-analysis

Combined analysis of multiple studies

sources

📖

Review

Comprehensive topic evaluation

sources

Overall assessment: Evidence level for this topic is strong. This page is supported by 2 guidelines, 2 systematic reviews/meta-analysis, 2 reviews.

📝 Questions to Ask Your Doctor

Be prepared for your appointment. Add questions to your list.

📋 References

[PMID: 38851997] EASL-EASD-EASO Clinical Practice Guidelines on the Management of Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD). Journal of Hepatology, 2024.

[PMID: 39094335] Global Prevalence of Nonalcoholic Fatty Liver Disease: An Updated Review Meta-Analysis comprising a Population of 78 million from 38 Countries. Archives of Medical Research, 2024.

[PMID: 36626630] The Global Epidemiology of Nonalcoholic Fatty Liver Disease (NAFLD) and Nonalcoholic Steatohepatitis (NASH): a Systematic Review. Hepatology, 2023.

[PMID: 36968618] Drug-induced liver injury: a comprehensive review. Therapeutic Advances in Gastroenterology, 2023.

[PMID: 27995906] ACG Clinical Guideline: Evaluation of Abnormal Liver Chemistries. American Journal of Gastroenterology, 2017.

[PMID: 10781624] Evaluation of Abnormal Liver-Enzyme Results in Asymptomatic Patients. New England Journal of Medicine, 2000.

Last reviewed: 3/27/2026

Next review: 3/27/2027

⚖️ Comparisons

ALT/AST vs GGT→

🔗 Related Topics

🩺 Yağlı karaciğer hastalığı (MASLD)🩺 Hepatit 🧪 GGT (gamma-glutamil transferaz)🧪 ALP (alkalen fosfataz)🧪 Bilirubin 🧪 Ferritin

⚖️ This page does not replace medical advice. Make treatment decisions with your doctor.
Content is based on scientific studies indexed in PubMed and current clinical guidelines.