Liver Function Tests Test
Liver function tests measure several substances in your blood to check how well your liver is working and whether it may be damaged.
What this test measures
Liver function tests measure albumin, total protein, ALP, ALT, AST, GGT, bilirubin, lactate dehydrogenase (LDH), and prothrombin time (PT) in a blood sample. These substances are made or processed by the liver.
What your results mean
Reference ranges vary by laboratory and by your age and sex. MedlinePlus does not publish a single normal range for this test — always read your result against the range printed on your own lab report and discuss it with your provider.
Higher-than-normal results
High levels of certain substances may indicate liver inflammation (hepatitis), bile duct problems, or liver damage from alcohol, infection, or medicines. However, high ALP can also be a sign of bone disease.
Frequently asked questions
What do liver function tests measure?
They measure albumin, total protein, ALP, ALT, AST, GGT, bilirubin, LDH, and prothrombin time in your blood.
Can liver function tests diagnose specific diseases?
No, they alone usually can't diagnose specific diseases. If results are abnormal, you'll need other tests to find the exact cause.
What can abnormal results mean?
Abnormal results can mean your liver is inflamed, you have hepatitis, your liver isn't working well, you have a bile duct problem, or medicines are harming your liver.
Do abnormal results always mean liver disease?
No, other conditions like bone disease can cause abnormal results. Your provider will consider your symptoms, medical history, and medicines.
What should I do if my results are abnormal?
Ask your provider to explain what your results mean. They may repeat the tests later if you've been ill, as abnormal results can be temporary.
Related lab tests
Sources
- MedlinePlus: Liver Function Tests — NIH MedlinePlus
Last updated . Information is aggregated from official public sources and is not a substitute for professional medical care.