Laboratory test
Liver function tests
Other names and abbreviations: ALT, AST, liver enzymes
The ALT and AST enzymes show whether liver cells are being damaged.
Raised liver enzymes can result from fatty liver, alcohol, medicines, infections, but also intense exercise (AST). The doctor may add GGT and bilirubin.
Typical ranges in adults
| Parameter | Typical range | What a deviation may mean |
|---|---|---|
| ALT | up to approx. 35–40 U/l | in women the range is often lower |
| AST | up to approx. 35–40 U/l | also rises after exercise and muscle injury |
The ranges are approximate and differ between laboratories; they also depend on age, sex and pregnancy. A result outside the range doesn't always mean illness – discuss it with a doctor.
When it is done
In preventive check-ups, when taking medicines that strain the liver, with overweight or alcohol use.
How to prepare
Fasting; no alcohol or intense training the day before.
