The First Steps With Liver Function Tests
Liver Function Tests: the few things that matter most, and the mistakes that catch people out early.
A panel of blood tests reflecting liver injury and function.
Key takeaways
- Common components: ALT, AST, ALP, GGT, bilirubin, albumin
- ALT and AST: markers of liver cell injury
- Most useful single change: Ask what specifically was abnormal rather than accepting "liver tests".
- Commonest mistake: Assuming normal results exclude liver disease.
- See a doctor if any of the signs under "When to speak to a doctor" below apply to you.
Why bother
They are frequently abnormal for benign reasons and frequently normal in significant disease, so they are a prompt rather than an answer.
Start here
Start with two. Add the rest once those have stopped taking effort.
- Ask what specifically was abnormal rather than accepting "liver tests"
- Ask about a fibrosis score such as FIB-4 if you have risk factors
Then add these
After that, these.
- Mention alcohol, supplements and all medicines honestly
- Have mildly abnormal results repeated before further investigation
The numbers, in one place
| Measure | Figure |
|---|---|
| Common components | ALT, AST, ALP, GGT, bilirubin, albumin |
| ALT and AST | markers of liver cell injury |
| ALP and GGT | markers of bile duct involvement |
| Albumin and clotting | the only true measures of liver function |
| Can be normal | even with significant fibrosis |
Common early mistakes
- Assuming normal results exclude liver disease
- Herbal and bodybuilding supplements, a recognised cause of liver injury
- Exceeding paracetamol dosing limits
Where to go next
- Liver Function Tests: A Practical Checklist
- Liver Function Tests: Common Myths and What Guidelines Say
- Liver Function Tests — the reference entry
- Hepatitis B and C: What the Evidence Actually Says
- What the Guidance Really Says About Cirrhosis
When to speak to a doctor
Seek urgent help for yellowing of the skin or eyes, dark urine with pale stools, severe abdominal pain, vomiting blood, or confusion. Contact a GP promptly for markedly abnormal results, or for abnormal results with fatigue, itching or weight loss.
Where this comes from
- NICE — Abnormal liver blood tests clinical knowledge summary
- British Liver Trust — liver blood tests
How this page was put together
Every figure, recommendation and warning above is taken from the guidance named in Where this comes from. Nothing on this page is inferred, summarised or generalised beyond what those bodies publish: where they give a number, it is their number, and where they are silent, so are we. Pages are rebuilt whenever the underlying record changes. Sign-off by a named clinician, where it has happened, is shown at the top of the page along with the date.
Medical disclaimer
This article is general information, not medical advice. It cannot account for your own history, medication or circumstances. Always speak to a GP, pharmacist or another qualified health professional before making changes that affect your treatment, and never delay seeking medical advice because of something you have read here. In an emergency, call 999.
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