What is ALT?
your main liver damage marker
ALT is an enzyme found almost exclusively in the liver. When liver cells are damaged, ALT leaks into the blood and the value rises. It is the most specific routine test for liver injury.
ALT rises in fatty liver, viral hepatitis, drug effects, alcohol use, and other liver disease. Mild elevations are common and can often be reversed with lifestyle change.
Test facts
- Unit
- µkat/L
- Sample
- Serum
- Fasting
- No fasting needed
- Turnaround
- 1 day
What does low ALT mean?
Low ALT is not clinically significant.
What does high ALT mean?
Mildly raised ALT often points to fatty liver. Markedly raised values need investigation for hepatitis or other acute liver disease.
Panels that measure ALT
- Deep Baseline
- Female Annual
- Male Annual
- Heart & Vessels
- Diabetes & Metabolic
- Metabolic Deep Dive
- Athlete Performance
- Liver Check
More markers in the same area
Launching in Stockholm in 2026.
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This is general information about the marker, not an assessment of your values and not medical advice. Last updated: May 2026.