Definition
What ALT measures
Alanine aminotransferase is an enzyme concentrated in liver cells. When liver cells are stressed or injured, ALT leaks into the blood, making it the most liver-specific enzyme on a routine panel.
Illustrative sample band · Synthetic
32U/L
3.1Sample target 10–35 U/L60
Why it matters
How clinicians usually read it
It is the workhorse marker for everyday liver stress from alcohol, medications, supplements, and fat accumulation in the liver — patterns worth catching early.
When it reads low
A lower value can mean
A low ALT is generally unremarkable. Values can run lower with age or low muscle mass and rarely need follow-up on their own.
When it reads high
A higher value can mean
A higher ALT can follow alcohol, recent hard exercise, medications, supplements, viral illness, or fatty liver. Persistent elevation deserves a clinician's work-up rather than a guess.
Questions for a clinician
Bring the number into a real conversation
01
Could alcohol, a medication, or a supplement explain this ALT?
02
How should ALT be read next to my AST and metabolic markers?
03
At what level or duration of elevation would you order imaging or more tests?
Educational boundary
Educational information only. Displayed ranges are illustrative sample bands, not a diagnosis, treatment plan, or substitute for the contracted laboratory report and a qualified clinician.
See it as a sample result
The sample dashboard shows an illustrative reading, target band, and trend for ALT.