ALT and AST: What Your Liver Enzyme Results Mean
ALT and AST are enzymes released when liver cells are stressed. Learn what mildly elevated liver enzymes mean, typical ranges, and the most common causes.
Understand your alt & ast in minutes
Upload your lab report and get a personalized explanation for every biomarker.
What it is
ALT (alanine aminotransferase) sits mostly inside liver cells, so it is the more liver-specific of the two. AST (aspartate aminotransferase) is also found in muscle and heart tissue.
Both leak into the blood when cells are damaged or stressed, which is why they are read together with ALP, bilirubin, and albumin as a liver panel.
Why it matters
The most common reason for mildly elevated ALT in adults is fatty liver related to insulin resistance, often alongside high triglycerides and central weight gain.
The AST-to-ALT ratio is a useful clue. A ratio above 2 points more toward alcohol-related liver injury; muscle injury raises AST much more than ALT.
Typical reference ranges
Ranges vary by lab and individual circumstances. These are common adult reference ranges for orientation only.
| Group | Common range |
|---|---|
| ALT (men) | 7–55 U/LSome labs use a stricter 30 U/L upper limit |
| ALT (women) | 7–45 U/LSome labs use a stricter 19–25 U/L upper limit |
| AST | 8–48 U/L |
| Marked elevation | > 3× upper limitNeeds prompt evaluation |
Not sure where your alt & ast falls? Upload your lab report and Nodava marks it against the range for you.
See where you fallWhat can move your result
Alcohol, intense or unaccustomed exercise, acetaminophen and statins, supplements, viral hepatitis, weight change, and thyroid disease all affect these enzymes.
Frequently asked questions
Can exercise raise liver enzymes?
What is a mildly elevated ALT?
Should I repeat abnormal liver enzymes?
Get the full picture from your lab report
ALT & AST is just one piece of the puzzle. Nodava explains every biomarker on your report, highlights what is out of range, and helps you track changes over time.
Upload my report