ALT (alanine aminotransferase) — also called SGPT — is a key liver enzyme measured on most blood panels. When your ALT is above the laboratory’s reference range, it can signal that liver cells are irritated or releasing more enzyme than usual.
Mild elevations are common and often temporary. Context matters: alcohol intake, medications or supplements, viral illness, or even recent strenuous exercise can all raise ALT for a short time.
Each laboratory defines its own reference range, but a typical adult upper limit for ALT is around
35–45 U/L.
Values just above that limit are commonly rechecked, while higher or persistent elevations may lead
to additional evaluation such as a full
liver function panel
or imaging (for example, ultrasound).
If ALT rises briefly after illness, medication use, alcohol intake, or strenuous exercise,
it often returns to normal within a few weeks.
| ALT level (U/L) | Typical category | How clinicians often interpret it |
|---|---|---|
| < 40 | Normal | Within a common reference range for many adult laboratories. |
| 40–79 | Mild elevation | Very common and often temporary; may be seen with recent illness, alcohol, medications or supplements, or intense physical activity. |
| 80–199 | Moderate elevation | More likely to prompt follow-up testing and review of risk factors such as metabolic health, alcohol use, and medication exposure. Interpretation depends on other markers (AST, ALP, bilirubin). |
| ≥ 200 | Marked elevation | Typically warrants timely medical evaluation, especially if persistent, accompanied by symptoms, or associated with other abnormal liver tests. |
Important: Numeric cutoffs above use a common example upper limit (~40 U/L). Always interpret ALT using the reference range shown on your own lab report.
Most people with a mildly elevated ALT do not have serious liver disease. Concern increases when ALT remains elevated on repeat tests, rises above two to three times the upper limit of normal, or appears alongside symptoms such as jaundice, dark urine, or unexplained fatigue.
It means your ALT level is above the reference range used by the lab. In many cases this reflects a mild and temporary liver enzyme rise, not a diagnosis by itself. Interpretation depends on how high the value is, whether it stays elevated, and how it compares with AST, ALP, and bilirubin.
Yes. Many people with elevated ALT feel completely well. Symptoms are more likely when elevations are marked, persistent, or accompanied by other abnormal liver tests.
No. ALT can rise temporarily due to recent illness, alcohol intake, medications or supplements, or strenuous exercise. Repeat testing often helps distinguish a short-term elevation from an ongoing issue.
Mild elevations just above the upper limit are common. ALT levels that remain two to three times above normal, or continue to rise on repeat tests, usually deserve closer medical evaluation.
Clinicians typically review trends over time and interpret ALT together with a full liver function panel, medical history, medications, and lifestyle factors. This broader context is often more informative than a single number.
The AI-LabTest interpretation engine analyzes your ALT and related liver markers using advanced medical reasoning frameworks. It compares trends — such as ALT/AST ratios, bilirubin levels, and ALP shifts — to explain what your numbers mean in context. The result is a clear, private summary you can review before your next doctor’s visit.
Is an ALT of 70 considered high?
In many laboratories, ALT values above the upper reference limit (often around 35–45 U/L) are considered elevated. A value around 70 U/L is usually in the mildly to moderately high range, especially if it stays elevated on repeat testing.
Can high ALT levels go back to normal?
Yes. ALT can return to normal once the main trigger is addressed — for example after recovery from a viral illness, adjusting medications, reducing alcohol intake, or improving metabolic factors such as weight and blood sugar. Follow-up testing helps confirm that it is trending back into range.
When should I worry about high ALT?
High ALT deserves closer attention when it is two to three times above the upper limit of normal, persists on repeated tests, or is accompanied by symptoms such as jaundice, dark urine, marked fatigue, abdominal pain, or other abnormal liver markers. In these situations, timely medical review is recommended.
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