Liver Function Tests (Liver Panel)
Reviewed
Also called: LFT, Liver panel, Liver profile, Hepatic function panel
Liver function tests are a group of blood measurements that can indicate liver injury, bile-flow problems, or aspects of liver function.
Specimen: Blood
Why this test may be ordered
- Investigating possible liver disease or injury
- Monitoring known liver disease
- Checking for medicine-related effects or risk factors
Preparation and collection
Preparation depends on the panel and laboratory. Fasting or medicine timing may be requested; do not stop medicines unless instructed.
A health professional usually takes a small blood sample from a vein. Collection normally takes only a few minutes.
Blood collection has a small risk of brief discomfort, bruising, light-headedness, or rarely infection at the needle site.
Understanding results
The pattern across enzymes, bilirubin, proteins, and clotting is usually more informative than one isolated result. Not every component directly measures liver function.
- One or more abnormal components: May reflect liver-cell injury, bile-flow obstruction, reduced synthesis, medicine effects, muscle or bone sources, or other illness. Limitation: The panel alone usually cannot identify a specific diagnosis. Next step: Review the pattern, symptoms, medicines, alcohol exposure, prior values, and targeted follow-up tests.
- Components within range: Measured components fall within the laboratory intervals. Limitation: Normal results do not exclude every liver condition. Next step: Interpret according to the reason for testing and risk profile.
- ALT, AST, ALP, GGT, bilirubin, albumin, and PT/INR answer different clinical questions.
- Exercise, muscle injury, pregnancy, medicines, alcohol, fasting, and sample quality can alter components.
What to do next
A clinician may repeat the panel or request hepatitis testing, ultrasound, autoimmune tests, medicine review, or other assessment based on the pattern.
- Which reference interval and units apply to my result?
- Could medicines, supplements, illness, or sample timing affect this result?
- Do I need a repeat test or another test before any conclusion is made?
Evidence source
U.S. National Library of Medicine: Liver Function Tests (Liver Panel)