BLOOD TEST · SMART CARE POLYCLINIC, DEIRA
ALT explained
The most liver-specific enzyme on the panel. It rises when liver cells are irritated.
What the ALT test measures
An enzyme that lives inside liver cells and almost nowhere else. When it appears in the blood it is because liver cells have leaked it. A mild rise is common and frequently not liver disease; how far to investigate follows the ACG liver-chemistry guideline.1
Reported as part of Liver Function Test.
What the result tells you
Mildly raised
Most often fatty liver, especially alongside extra weight or raised blood sugar. Frequently reversible.
Substantially raised
Points towards viral hepatitis, a drug reaction or heavy alcohol. Investigated rather than watched.
Read against AST
ALT the higher of the two fits fatty liver or viral hepatitis. AST clearly higher makes alcohol more likely.
Often overlooked
Herbal and bodybuilding supplements are a common cause. Bring the bottle rather than the name.
How to prepare
- Fasting
- Not needed for ALT, but usually taken with a fasting panel
- Best time
- Morning, with the rest of the panel
- Avoid before
- Alcohol for 2–3 days
- Heavy exercise for 2–3 days
What can move the result
A result outside the usual range does not on its own mean something is wrong. These are the everyday explanations a doctor considers first.
Frequently asked questions
An enzyme that lives inside liver cells and almost nowhere else. When it appears in the blood it is because liver cells have leaked it. A mild rise is common and frequently not liver disease; how far to investigate follows the ACG liver-chemistry guideline. Mildly raised: Most often fatty liver, especially alongside extra weight or raised blood sugar. Frequently reversible.
Fasting: Not needed for ALT, but usually taken with a fasting panel. Best time: Morning, with the rest of the panel. Avoid beforehand: Alcohol for 2–3 days; Heavy exercise for 2–3 days.
Commonly: fatty liver, the commonest cause of a mild rise; alcohol, including one heavy episode days before; paracetamol, some cholesterol tablets, some antibiotics; viral hepatitis; herbal and bodybuilding supplements. A single result is not a diagnosis. Values are read against the laboratory's own reference range and alongside your history, your symptoms and the rest of the panel — which is why every package includes a doctor to go through them with you.
At Smart Care Polyclinic, 29 Doha Centre, Al Maktoum Rd, Deira, Dubai. Walk in during opening hours or call +971 (0)4 379 3562.
Sources
Written from current guidance and reviewed 31 August 2026.
Sources cited above
- Kwo PY, Cohen SM, Lim JK. ACG Clinical Guideline: Evaluation of Abnormal Liver Chemistries. The American Journal of Gastroenterology. 2017;112(1):18-35. PMID 27995906. doi:10.1038/ajg.2016.517The American College of Gastroenterology guideline on what a raised liver enzyme actually means and how an abnormal result should be worked up.
Sources are listed for the specific statements they support. They are published research and guidance, not a substitute for a consultation — what applies to you is decided by a doctor who has assessed you.
- ALT blood testMedlinePlus, US National Library of Medicine
- Evaluation of abnormal liver chemistriesAmerican Association for the Study of Liver Diseases
- Liver function testNHS