ALT (SGPT) — What It Means in Your Blood Test
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ALT is an enzyme that leaks from your liver cells into your blood when they are stressed or hurt.
ALT (SGPT) is a quick window into how comfortable your liver cells are right now. When this reading climbs, it is a gentle signal that those cells may be under pressure.
Also known as: SGPT, Alanine Aminotransferase, ALT/SGPT, Alanine Transaminase, GPT
This isn't a case where higher or lower is better. Your body keeps it in a narrow band, and both directions can matter.
Last reviewed: 2026-08-16
What does ALT (SGPT) do in your body?
Because this marker sits mostly inside one organ, a rise points fairly squarely at the liver. That focus makes it a useful early read on whether those cells are settled or strained, well before you would notice anything yourself [AASLD, 2023]. Everyday things like weight or alcohol can nudge it too.
ALT is like a smoke alarm wired mainly to your liver: it goes off when those cells are in distress.
What is ALT (SGPT)?
This enzyme sits inside liver cells and helps them process amino acids for energy. Damage to the cell membrane releases the enzyme into the bloodstream, raising the measured level.
Why is ALT (SGPT) tested?
You have this test to check the health of your liver cells and to look for possible injury to them.
What is a normal ALT (SGPT) range?
- India
- No India-specific national reference interval is published for this parameter; your lab's printed range is the most reliable comparison.
- Global
- 7–56 U/L (males); 7–45 U/L (females)
Ranges vary by lab, method and equipment — the range printed on your own report is the one that applies to your result.
Source: [AASLD, 2023]
What does your ALT (SGPT) value mean?
There is no widely-accepted set of value bands for this parameter. Compare your result with the reference range printed on your own report, and discuss it with your doctor.
What does a high ALT (SGPT) result mean?
A high level can mean your liver cells are inflamed or hurt. It is worth discussing with your doctor.
What does a low ALT (SGPT) result mean?
A very low level is usually not a concern and is common in healthy people.
What can affect your ALT (SGPT) result?
- Body weight
- Alcohol
- Hard physical exercise
- Some medicines and supplements
- Time of day of the test
Questions to ask your doctor
About this result
- What does my ALT (SGPT) result mean for me specifically, given my age and health?
- Is my ALT (SGPT) in the range that is right for me, not just the lab's general range?
What to do next
- Could anything I eat, do, or take have affected my liver enzyme result?
- Is there anything I should do about my ALT (SGPT), or is it fine to leave as it is?
About retesting
- Does my ALT (SGPT) need to be repeated, and if so, when?
- The typical range for ALT (SGPT) can vary between labs — should I compare my result against my own lab's printed range?
The bigger picture
- Should my ALT (SGPT) be looked at together with my Total Bilirubin and Direct Bilirubin result?
- Does my ALT (SGPT) connect to any condition I already have, or to anything I have noticed in how I feel?
Frequently asked questions
- What is ALT (SGPT)?
- This enzyme sits inside liver cells and helps them process amino acids for energy. Damage to the cell membrane releases the enzyme into the bloodstream, raising the measured level. You have this test to check the health of your liver cells and to look for possible injury to them.
- What is a normal liver enzyme test range?
- A typical adult range is around 7–56 U/L (males); 7–45 U/L (females). No India-specific national reference interval is published for this parameter; your lab's printed range is the most reliable comparison. Ranges vary by lab, method and equipment — the range printed on your own report is the one that applies to your result.
- What does a high ALT (SGPT) result mean?
- A high level can mean your liver cells are inflamed or hurt. It is worth discussing with your doctor.
- What does a low ALT (SGPT) result mean?
- A very low level is usually not a concern and is common in healthy people.
- What can affect your ALT (SGPT) result?
- Several everyday factors can influence it, including Body weight, Alcohol, Hard physical exercise, Some medicines and supplements, Time of day of the test.
Sources
- AASLD (2023) — Practice Guidance on Evaluation of Hepatic Function Tests
- CLSI (2010) — EP28-A3c Reference Interval Guidelines
Part of the Liver Function
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