ALT

LiverLiverBlood

Alanine transaminase (ALT) is an enzyme mainly found in the liver, though it exists in other parts of the body.

Why it matters: ALT levels in the blood can increase when the liver is damaged, so the test is used to help assess liver health. A raised result does not by itself mean a severe liver condition.

Source · Cleveland Clinic — what it is, why it matters, what moves it, related conditions

Reference Range
< 45.0U/L
45NormalHigh
What Moves It

May increase with:

Alcohol-induced liver injury
Fatty liver disease
Hepatitis
Cirrhosis
Liver tumors
Hemochromatosis
Mononucleosis
Some medicines

May decrease with:

Vitamin B6 deficiency
Chronic kidney disease
Associated Conditions
Alcohol-induced liver injury, which an increased level may indicateFatty liver disease, which an increased level may indicateHepatitis, or liver inflammation, which an increased level may indicateCirrhosis, or scarring of the liver, which an increased level may indicateLiver tumour or liver cancer, which an increased level may indicateLiver ischaemia, where too little blood flow leads to death of liver tissue, which an increased level may indicateHaemochromatosis, or too much iron in the body, which an increased level may indicateMononucleosis, which an increased level may indicateVitamin B6 deficiency, which a lower than normal level could indicateChronic kidney disease, which a lower than normal level could indicate
Related Markers
ASTGGTalpBilirubin (Total)Albumin
Common questions

What is ALT?

Alanine transaminase (ALT) is an enzyme mainly found in the liver, though it exists in other parts of the body.

What might a high or low ALT mean?

ALT levels in the blood can increase when the liver is damaged, so the test is used to help assess liver health. A raised result does not by itself mean a severe liver condition.

What is the typical reference range for ALT?

The general-population reference range shown here is < 45 U/L. Reference ranges describe the general population and are not a personal target — discuss your results with your physician.

What can affect ALT?

It may be higher with: Alcohol-induced liver injury, Fatty liver disease, Hepatitis, Cirrhosis, Liver tumors, Hemochromatosis, Mononucleosis, Some medicines. It may be lower with: Vitamin B6 deficiency, Chronic kidney disease.

More in Liver
AlbuminAlkaline PhosphataseASTBilirubin (Direct)Bilirubin (Indirect)Bilirubin (Total)GGTLDH

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