ALT is a liver enzyme that helps check how healthy your liver cells are.
Alanine aminotransferase (ALT) is an enzyme found mostly inside liver cells. It helps the liver turn protein into energy.
When liver cells are damaged or inflamed, they leak ALT into the blood, so the level in your blood is a sensitive sign of liver health.
A raised ALT usually points to the liver. Common causes are fatty liver, alcohol, viral hepatitis, and some medicines. Because ALT sits mainly in the liver, it is one of the most specific blood markers of liver cell damage.
A low ALT is not a concern. The value is most useful read together with AST and GGT to build a picture of what is happening in the liver.
Aniva reads your result against research-backed ranges, not just the lab's wide normal. The reference shown below is specific to this biomarker.
| Group | Serum ALT (SI) |
| Men | up to ~50 U/L |
| Women | up to ~35 U/L |
Ranges are guidance only and vary by lab, assay, and sex. Many German labs follow IFCC standardised limits. Read your result against your own lab's reference interval, in line with DGKL practice.
Strenuous exercise and muscle injury can raise ALT a little, since some is found outside the liver. Many medicines and supplements affect it. Haemolysis of the sample can alter the reading. Fasting is not required.
Best read with AST, GGT, and alkaline phosphatase, and the AST to ALT ratio helps separate alcohol related from other liver injury.
What does a high ALT mean? It suggests your liver cells are irritated or stressed. Causes include medicines, alcohol, infections, or fatty liver.
Do I need to fast for an ALT test? No. Fasting is not required for ALT.
What can affect my ALT result? Recent alcohol, hard workouts, muscle injury, illness, or certain medicines and herbal supplements can change values.
How often should I check ALT? It depends on your situation. Many people recheck within weeks to months after changes or if elevated.
How long do results take? Results are usually ready in about 7 days.
What should I discuss with my clinician? Share all medicines and supplements, alcohol use, and recent exercise or illness to guide next steps.
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