There isn't a single "best" ALT range, as the normal range for alanine transaminase (ALT) varies depending on the laboratory conducting the test and the individual's sex. Several sources provide slightly different ranges, highlighting the importance of considering the specific laboratory's reference values.
Understanding ALT and its Ranges
ALT is a liver enzyme, and elevated levels often indicate liver damage or disease. However, the normal range varies. Different laboratories use different methods and may have slightly different reference ranges. It's crucial to interpret ALT results in the context of the specific laboratory's reference range.
Several sources report the following common ranges:
- 7 to 56 U/L: This range is frequently cited by multiple sources, including Cleveland Clinic and WebMD. https://my.clevelandclinic.org/health/diagnostics/22028-alanine-transaminase-alt, https://www.webmd.com/digestive-disorders/alanine-aminotransferase-test
- 4 to 36 U/L: UCSF Health provides this range as a common reference. https://www.ucsfhealth.org/medical-tests/alanine-transaminase-(alt)-blood-test
- 0 to 45 IU/L: Cleveland Clinic lists this range in a broader context of liver function tests. https://my.clevelandclinic.org/health/diagnostics/17662-liver-function-tests
- 30 to 50 U/L: An older study referenced a normal range in this area, highlighting that these reference ranges can evolve over time. https://www.aafp.org/pubs/afp/issues/2002/1115/p1991.html
It's important to note that ALT levels are typically higher in males than in females.
Interpreting Your Results
Always compare your ALT results to the range provided by the specific laboratory that performed the test. An ALT level outside the normal range for that lab warrants further investigation and consultation with a healthcare professional to determine the cause.
