Skip to main content
Your session has expired. Reloading...
Liver

ALT and alcohol: what the liver enzyme shows about the liver

ALT (alanine aminotransferase) is an enzyme in the liver cells: according to the NVKC, a protein that helps cells convert one substance into another. According to Thuisarts, the liver breaks down substances from the blood, including certain medicines, waste products, alcohol and drugs.

With damage to liver cells, ALT leaks from the liver into the blood according to the NVKC; according to Thuisarts, alcohol is one of the possible causes of abnormal liver tests. Whether ALT is raised can only be seen with a blood test.

Unilabs gives 0 to 45 U/l for men and 0 to 34 U/l for women from age 19 as the reference values for ALT.

Doctor's Assessment Included

ALT is an enzyme, a protein that helps cells convert one substance into another; it is found mainly in the liver and enters the blood when liver cells are damaged. The four laboratories use an adult upper limit of 45 U/l for men and 34 U/l for women.

  • According to the NVKC, a slightly raised ALT without symptoms is not given a meaning straight away; only when the value is more than twice the upper limit is a search for the cause advised.
  • A normal or slightly raised ALT does not rule out serious liver disease such as cirrhosis, which is why ALT is often combined with other liver tests.
  • According to Thuisarts, when ALT is only slightly high, there is no clear cause and the person is not really ill, the GP can wait a few weeks and then test the blood again.

Reference Ranges

See the value that applies to you:

Choose male or female — this range differs by sex.

Enter your age — this range changes with age.

This range also depends on context such as cycle phase or sample material; the highlighted rows apply to your group.

Your reference range
u/l
9 71 u/l
Reference ranges by group, in u/l
Male · 1–5 years 9–35 u/l
9 35
Male · 6–12 years 10–35 u/l
10 35
Male · 13–18 years 9–42 u/l
9 42
Male · 19–50 years 13–71 u/l
13 71
Male · 51–65 years 13–64 u/l
13 64
Male · 66–80 years 11–54 u/l
11 54
Male · 81 years and older 9–42 u/l
9 42
9 71 u/l

Source: NVKC Reference population: Dutch general-practice population (NUMBER, n = 7,574,327)

Reference ranges may vary between laboratories. When you order a test, a BIG-registered doctor assesses your personal results in context. For treatment decisions, discuss your results with your GP.

Check your own value

ALT (Alanine Aminotransferase): what Dutch laboratories use

Reference ranges by group, in u/l
Star-shl · Male 0–45 U/l
0 45
Unilabs · Male · 19 years and older 0–45 U/l
0 45
Certe · Male · 18 years and older · a limit, not a range < 45 U/L
45
Diagnostiek voor U · Male · a limit, not a range < 45 U/L
45
0 49.5 u/l

Source: Star-shl

Source: Unilabs

Source: Certe

Source: Diagnostiek voor U

Each value as the laboratory itself publishes it, retrieved in 2026.

ALT (Alanine Aminotransferase): what this test measures

In the blood, the ALT test measures ALT enzyme activity in U/l, and according to the NVKC the result is compared with gamma-GT among other tests. According to the BSG, gamma-GT is most often raised by obesity or excess alcohol use, or possibly by medicines.

ALT (Alanine Aminotransferase): why this value matters

According to the BSG, an ALT that is only mildly or moderately raised also fits the most common causes of abnormal liver tests that lead to chronic liver disease, including alcohol-related liver disease.

ALT (Alanine Aminotransferase): how the blood test works

Referral
No GP referral needed. After the order we arrange the referral through ZorgDomein, within one business day; orders after 17:00 or at the weekend start on the next business day. ZorgDomein emails a barcode, and that barcode is what the draw site needs.
The draw
A blood draw from a vein in the arm, at a partner laboratory's draw site. No home kit, no finger prick.
Which test
Metabolic Health Check · €129,- · Complete Metabolic Panel · €149,- · Men Over 40 Panel · €279,- · Complete Men's Health Panel · €289,-
Where
650+ draw sites run by independent laboratories across the Netherlands. Draw sites

ALT (Alanine Aminotransferase): how to prepare

  1. Better no hard training beforehand

    Recommended

    Hard exercise in the 48 hours before can raise this value temporarily. Plan the draw on a rest day if you can.

  • Water is always fine. Drink as usual beforehand, it makes the draw easier.
  • Take your usual medication, unless your own doctor told you otherwise.

ALT (Alanine Aminotransferase): when is testing worthwhile?

For people who drink too much alcohol, according to the NVKC a doctor requests an ALT test, among other situations.

ALT (Alanine Aminotransferase): symptoms of a high or low value

Low Levels

A low ALT can be linked with vitamin B6 deficiency in long-term heavy drinking: according to Malakouti and colleagues, most chronic alcoholics have such a deficiency, and it lowers the production of ALT more than that of AST.

High Levels

According to Thuisarts, drinking alcohol can make liver tests such as ALT abnormal. A fatty liver, which according to Thuisarts can develop from drinking a lot of alcohol among other things, is also among Thuisarts' possible causes of abnormal liver tests. According to Malakouti and colleagues, an AST:ALT ratio of 2:1 or more should make a doctor strongly suspect alcohol-related liver injury.

ALT (Alanine Aminotransferase): causes of a low or high value

What lowers the value

  • Low muscle mass

    In studies of the general population, a low ALT goes together with loss of muscle mass.

  • Vitamin B6 deficiency

    Vitamin B6 is needed to make ALT; a deficiency, which is common with long-term heavy drinking, reduces how much ALT is made.

What raises the value

  • Fatty liver

    A fatty liver, too much fat in the liver, can raise ALT and the other liver tests in the blood.

  • Alcohol

    Drinking alcohol is one of the causes of a raised ALT and other raised liver tests.

  • Medicines and drugs

    Medicines that can damage the liver, including ones bought without a prescription, and drugs such as cocaine or ecstasy can raise ALT and the other liver tests.

  • Acute viral hepatitis

    An ALT more than 15 times the upper limit is almost always caused by acute hepatitis, which is usually caused by a virus.

  • Heavy weight training

    In one study, ALT stayed raised for at least 7 days after an hour of heavy weight training in healthy men who were not used to it.

ALT (Alanine Aminotransferase): lifestyle and this value

With a raised ALT and alcohol use, Thuisarts advises stopping alcohol for a while, after which the GP can check after a few weeks whether the liver tests have improved.

ALT (Alanine Aminotransferase): frequently asked questions

How long until ALT is normal again after acute hepatitis?

According to the NVKC, after acute hepatitis ALT stays strongly raised for 1 to 2 months, and the result is only normal again after 3 to 6 months.

Does a higher ALT mean the liver is in worse shape?

Not necessarily: according to the BSG, the idea that the height of an abnormal liver test such as ALT tracks the outcome is not supported by the literature. According to the BSG, the diagnosis and the reason for the test determine the course more clearly.

ALT (Alanine Aminotransferase): sources

  1. den Elzen WPJ, Brouwer N, Thelen MH, Le Cessie S, Haagen I-A, Cobbaert CM. NUMBER: standardized reference intervals in the Netherlands using a 'big data' approach. Clin Chem Lab Med 2018;57(1):42-56. (retrieved 2026) doi.org
  2. Star-shl, Labbepalingen (referentiewaarden per bepaling), star-shl.nl, geraadpleegd 2026-10-01 (retrieved 2026) star-shl.nl
  3. Unilabs, Bepalingenklapper (referentiewaarden per bepaling), bepalingenklapper.nl, geraadpleegd 2026-10-01 (retrieved 2026) bepalingenklapper.nl
  4. Certe, Bepalingenwijzer (referentiewaarden per bepaling), bepalingenwijzer.certe.nl, geraadpleegd 2026-10-01 (retrieved 2026) bepalingenwijzer.certe.nl
  5. Diagnostiek voor U, eLabgids (Referentiewaarden DvU), diagnostiek.getincontrol.eu, geraadpleegd 2026-10-01 (retrieved 2026) diagnostiek.getincontrol.eu
  6. Laufer M, et al. Low Alanine Aminotransferase, as a Marker of Sarcopenia and Frailty, Is Associated with Shorter Survival Among Prostate Cancer Patients and Survivors. Eur Urol Open Sci 2023. (retrieved 2026) pmc.ncbi.nlm.nih.gov
  7. Malakouti M, et al. Elevated Liver Enzymes in Asymptomatic Patients - What Should I Do? J Clin Transl Hepatol 2017;5(4):394-403. (retrieved 2026) pmc.ncbi.nlm.nih.gov
  8. NHG, Thuisarts.nl: De levertesten van mijn bloed zijn niet goed, geraadpleegd 2026-10-06 (retrieved 2026) thuisarts.nl
  9. NVKC, Alles over testen: ALAT, allesovertesten.nl, geraadpleegd 2026-10-06 (retrieved 2026) allesovertesten.nl
  10. Pettersson J, et al. Muscular exercise can cause highly pathological liver function tests in healthy men. Br J Clin Pharmacol 2008;65(2):253-259. (retrieved 2026) pmc.ncbi.nlm.nih.gov

Test Products

This marker is included in the following test panels.

Heart and blood vessels

Complete Metabolic Panel

Comprehensive metabolic panel: electrolytes, kidney, liver, glucose, HbA1c, and protein.

HbA1c (Glycated Hemoglobin) ALT (Alanine Aminotransferase) Calcium ALP (Alkaline Phosphatase) AST (Aspartate Aminotransferase) Bilirubin (Total) Urea (BUN) Creatinine eGFR (Estimated Glomerular Filtration Rate) Glucose (Fasting) Bicarbonate Chloride Sodium Potassium Albumin Total Protein Bilirubin (Direct) Bilirubin (Indirect)
€149,-
Prostate

Men Over 40 Panel

Age-appropriate screening including testosterone and PSA.

HbA1c (Glycated Hemoglobin) PSA (Prostate-Specific Antigen) ALT (Alanine Aminotransferase) TSH (Thyroid Stimulating Hormone) Triglycerides Creatinine Free T4 (Thyroxine) LDL Cholesterol SHBG (Sex Hormone Binding Globulin) Total Cholesterol Vitamin D (25-OH) Free Testosterone Total Testosterone hs-CRP (High Sensitivity CRP) HDL Cholesterol eGFR (Estimated Glomerular Filtration Rate) Cholesterol/HDL Ratio Non-HDL Cholesterol LDL/HDL Ratio
€279,-
Testosterone

Complete Men's Health Panel

A broad men's health panel: hormones, heart, metabolic, and organ function in one blood draw.

HbA1c (Glycated Hemoglobin) ALT (Alanine Aminotransferase) TSH (Thyroid Stimulating Hormone) Triglycerides Creatinine Glucose (Fasting) Free T4 (Thyroxine) LDL Cholesterol SHBG (Sex Hormone Binding Globulin) Total Cholesterol Vitamin D (25-OH) Free Testosterone Total Testosterone Ferritin hs-CRP (High Sensitivity CRP) HDL Cholesterol eGFR (Estimated Glomerular Filtration Rate) Cholesterol/HDL Ratio Non-HDL Cholesterol LDL/HDL Ratio
€289,-

Medical reviewer

Medical standards

Dr. Naimi oversees the medical standards behind our content and assessments.

Medical policy
CIBG Ministerie van Volksgezondheid,
Welzijn en Sport Official BIG registration BIG 49928676701 Opens in a new tab

ALT (Alanine Aminotransferase)

€8,-