What does a raised ALT mean?

A raised ALT can indicate the liver is irritated or stressed, with many possible causes ranging from minor and temporary (such as some medicines or recent alcohol) to ones needing follow-up. Mildly raised ALT is common. It should be interpreted by a doctor alongside your other liver results, symptoms and history rather than in isolation.

Should I worry about a slightly high ALT?

A slightly raised ALT is common and often has a minor or temporary cause, but it should still be reviewed by a doctor, who interprets it alongside your other liver tests and health. Sometimes a repeat test is advised. This tool cannot tell you the cause; it only shows where your value falls within a general reference range.

Is this tool a diagnosis?

No. This tool is for general education only and does not diagnose any condition. Liver function is assessed using several tests together, and results must be interpreted by a doctor who considers your full liver panel, symptoms, history and the specific reference range from your laboratory.

Lab Results & Test InterpretationGlobal

Liver Function (ALT) Interpreter

Understand where your ALT liver enzyme result falls within general reference ranges.

Written byAikins Apreku

Reviewed byDeborah Adotso, General Nurse

Updated June 2026

Your ALT level (U/L)

ALT (alanine aminotransferase) is one of the main liver enzymes on a liver function test. Reference ranges vary between laboratories — check the range on your own result.

What this tool does

This tool shows where your ALT liver enzyme result falls within a commonly used reference range, and explains in general terms what that area typically means. It is an educational reference tool, not a diagnosis. Liver function is assessed using several tests together, and reference ranges vary between laboratories, so your result must be interpreted by a doctor in the context of your full liver panel, symptoms and history.

About ALT and liver tests

ALT (alanine aminotransferase) is an enzyme found mainly in the liver. When liver cells are stressed or damaged, ALT can be released into the blood, so a raised level can be a sign of liver irritation. However, ALT is just one part of a liver function test, which includes other measures such as AST, ALP and bilirubin. A doctor looks at the whole pattern, not a single value, to understand what is happening.

Frequently Asked Questions

A commonly used reference range for ALT is up to around 40 U/L, but ranges vary between laboratories and can differ for men and women. The range printed on your own result is the one that applies to you. ALT is interpreted alongside other liver tests, so a doctor's assessment is needed rather than the number alone.

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Sources & References

LifeCheckIQ content is based on peer-reviewed research, recognised clinical guidelines, and authoritative medical sources, and is reviewed by Deborah Adotso, General Nurse, for clinical accuracy.

Medical Disclaimer: This tool is for informational and educational purposes only. Results are not a medical diagnosis. Always consult a qualified healthcare professional for medical advice, diagnosis, or treatment. In an emergency, call your local emergency number or visit the nearest hospital immediately.