Of all the liver values on your result, one truly matters if you may look at a single number: ALAT. It is found almost only in your liver cells, so when it rises, you know where to look. My take: if you want to screen your liver health with one marker, ALAT is the logical choice, and that is exactly why it is a shame that many people do not know how to read their number.
ALAT is one of the four core values in a liver panel. For the full picture, read our overview understanding liver values: ALAT, ASAT and gamma-GT.
What is ALAT?
ALAT (alanine aminotransferase) is an enzyme involved in amino-acid metabolism. It is the most liver-specific enzyme measured routinely. Although ALAT also occurs in small amounts in kidneys, heart and muscle, a raised ALAT almost always points to a liver problem.
Normal ALAT values
- Men: less than 45 U/L
- Women: less than 35 U/L
Some labs and guidelines use lower upper limits (men: 35 U/L, women: 25 U/L) for better detection of liver disease at an early stage. If your ALAT sits between that stricter limit and the standard upper limit, that is no alarm, but it is a good moment to look critically at alcohol, weight and sugar. Many people sit exactly in that grey zone and benefit from steering early, precisely because symptoms are absent at this stage.
How high is too high? Read your number
| Degree of rise | How to read it | What to do |
|---|---|---|
| 1 to 2x the upper limit | Mildly raised | Review lifestyle, repeat test |
| 2 to 5x the upper limit | Moderately raised | Further work-up with a doctor |
| 5 to 10x the upper limit | Clearly raised | Active liver damage, see a doctor |
| More than 10x the upper limit | Strongly raised | Immediate medical review |
Causes of a raised ALAT
A raised ALAT value can have various causes, from harmless to serious:
Common causes
- Non-alcoholic fatty liver (NAFLD): the most common cause in the Netherlands, linked to overweight and metabolic syndrome.
- Excessive alcohol use: alcohol damages liver cells directly.
- Medicines: statins, paracetamol (at high doses), antibiotics and some herbal supplements.
- Viral hepatitis: hepatitis B and C can cause chronic liver inflammation. The Dutch public-health institute (RIVM) tracks national hepatitis figures.
- Intense physical exertion: can cause a temporary, harmless ALAT rise.
Less common causes
- Autoimmune hepatitis
- Haemochromatosis (iron overload)
- Wilson's disease (copper overload)
- Coeliac disease
What can you do about a raised ALAT?
- Limit alcohol: even moderate use can cause complaints in a sensitive liver. The Dutch Health Council (Gezondheidsraad) advises none, or at most one glass a day.
- Work towards a healthy weight: 5 to 10% weight loss can significantly improve fatty liver.
- Check your medicines: discuss with your doctor whether drugs may play a role.
- Get further testing: ASAT, gamma-GT, albumin and possibly a liver ultrasound.
- Repeat the test: a one-off raised ALAT can be temporary; a repeat after 4 to 6 weeks gives more clarity.
What does your doctor do after a raised ALAT?
A raised ALAT is a starting point, not an end point. Your doctor usually places the value in a broader picture before drawing conclusions. What often happens:
- Repeat test: after 4 to 6 weeks, to see whether the rise persists or was a chance spike.
- Broader liver panel: adding ASAT, gamma-GT and alkaline phosphatase to read the pattern.
- Asking about lifestyle and medication: alcohol, weight, recent exercise, supplements and medicines.
- Liver ultrasound: if fatty liver is likely or the values keep deviating.
The ASAT/ALAT ratio helps give direction: a ratio under 1 fits fatty liver more, a ratio over 2 points more towards alcohol. That way one number becomes part of a logical story.
How do you prepare for an ALAT test?
A few simple things make your result more reliable. Avoid alcohol for at least 48 hours before the draw, since even an evening of drinking can temporarily raise your liver values. Skip intense strength training or a long endurance effort in the days before, because muscle damage can raise mainly ASAT, but sometimes ALAT too. Tell your doctor if you recently trained hard or started new supplements or medicines. For ALAT alone you do not need to fast, but if glucose and cholesterol are drawn at the same time, fasting is advised.
Frequently asked questions
Do I need to fast for an ALAT test?
Fasting is not strictly required for ALAT. If you also measure glucose and cholesterol, fasting is recommended.
Can I have a raised ALAT without symptoms?
Yes, that is even common. The liver has no nerve endings, so liver damage usually causes no pain or symptoms early on. That is exactly why a blood test is valuable as screening.
How quickly does ALAT normalise after stopping alcohol?
With alcohol-related ALAT rises, the value usually normalises within 2 to 4 weeks of stopping or strongly reducing alcohol.
Is your value raised? Read what you can do about high liver values, or have your values measured with the complete metabolic panel from Vital Check, with a doctor's review.
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