Liver
ALT (Alanine Aminotransferase)
Liver
Liver-specific enzyme. Most specific marker for liver cell damage.
VAT-exempt medical service
ALT is an enzyme found mainly in liver cells. When liver cells are damaged, ALT leaks into the blood, which makes it one of the more sensitive early markers of liver injury. It is usually measured together with AST, ALP and GGT, since the pattern between them says more than any single value.
Your liver is remarkably forgiving, but it has its limits. Alcohol, extra weight, medications, viral exposure, even your daily diet -- they all leave a mark. An ALT test lets you see that mark before it becomes a problem. Track it over time and you get a real-time picture of how your lifestyle choices are landing. That's not just data. That's power.
What a high value can mean
Elevated ALT usually points to liver trouble. Acute hepatitis -- from a virus, heavy drinking, toxins, certain medications, or an autoimmune flare-up -- can send ALT through the roof, sometimes taking months to settle back down. Fatty liver disease, obesity, and chronic liver cell damage are other common culprits. Your body might signal this with yellowing skin or eyes, stubborn fatigue, pain in the upper right abdomen, nausea, dark urine, loss of appetite, or persistent itching.
What a low value can mean
Low ALT? That's usually perfectly fine. In rare cases, very low levels might hint at a vitamin B6 deficiency or chronic alcohol use. Most people with low ALT feel completely normal, though some may notice mild fatigue or a dip in appetite.
Skip the fatty foods and alcohol the day before. Bring valid ID on test day.
Order your test
Choose your test and pay online. Your lab referral is created straight away.
Give your sample
Visit any of our partner sampling locations. No appointment needed at most of them.
The lab analyses it
Your sample is analysed at an accredited Swedish laboratory.
Get your results
Your values appear in your account with reference ranges and an explanation of each marker.
Both are liver enzymes, but ALT is largely confined to the liver while AST is also present in heart and skeletal muscle. ALT is therefore the more liver-specific of the two, and the ratio between them helps indicate the cause of liver injury.
A tough workout can bump ALT up a little thanks to muscle breakdown. Nothing dramatic, but skip the heavy session the day before testing for the cleanest results.
If everything looks good, once a year as part of a general check-up is plenty. If levels are elevated, your doctor might want to retest every few weeks to months to keep an eye on things.
Absolutely. Cut back on alcohol, lose some weight, treat an infection -- address the root cause and ALT often comes right back down.