Reading & Interpreting Your Liver Function Test

Reading & Interpreting Your Liver Function Test

Tests for liver function involve testing the blood to diagnose liver diseases and determine how well the liver carries out its normal functions. Some tests will measure the level of specific proteins in your blood. Others will check for the presence and amount of enzymes produced by liver cells in response to disease or damage.

Average Ranges for Liver Function Testing

Aspartate transaminase (AST)

AST levels higher than 10 to 40 units/L in men and 9 to 32 units/L in women may indicate reduced liver function.


Alanine transaminase (ALT)

ALT levels higher than 29 to 33 international units per liter (IU/L) in men and 19 to 25 IU/L in women may be a sign of liver disease.


Alkaline phosphatase (ALP)

The average range for ALP tests is 44 to 147 IU/L. Higher levels may point to problems with the liver.


Gamma-glutamyltransferase (GGT)

The normal range for GGT levels in the blood is 9 to 48 U/L. Liver disease or damage may result in higher levels.


L-lactate dehydrogenase (LDH)

The normal range for LDH levels in the blood is 140 – 280 U/L in adults. Higher than normal levels may point to liver damage or disease.


Prothrombin time (PT)

Refers to the time it takes your blood to clot. Levels higher than 9.4 to 12.5 seconds could point to liver damage or the presence of blood-thinning drugs.



Normal bilirubin levels are 1.2 milligrams per deciliter (mg/dL) in adults and 1 mg/dL in minors. For direct bilirubin tests, the normal range is 0.3 mg/dL. Higher bilirubin levels could be indicative of liver disease or damage.

Albumin and total protein

Healthy albumin levels range from 3.5 to 5.5 grams per deciliter (g/dL), and normal total protein levels range from 6.0 to 8.3 g/dL. Lower levels may indicate liver damage or disease.


Has at-home liver function testing indicated that you may have liver disease? Reach out to Prestige ER right away. We’ll conduct a more comprehensive tests of liver function, as well as any additional tests to help you figure out the most suitable treatment options. 

Visit Prestige ER for a Test of Liver Function Today