What is fatty liver?
The liver processes what you eat and drink and keeps the fat and sugar balance in order. If it structurally receives more than it can get rid of, especially with belly fat and a body that listens poorly to insulin, it stores fat in its own cells; fructose from soft drinks and fruit juice is converted directly into liver fat in the process. That is reversible in itself. In a small share of people the fatty liver becomes inflamed, and that inflammation can form scars over time: fibrosis, and in a small share of those cirrhosis. The liver does not complain. Fatty liver gives no complaints and is usually a chance finding: a slightly raised ALT in a blood test done for another reason, or fat on an ultrasound of the abdomen. ALT is the most specific liver value, gamma-GT sensitive but non-specific. Anyone who wants to read the liver therefore reads ALT, and beside it the fats and the sugar, because those tell where the fat comes from. The FIB-4 turns age, ALT, AST and platelets together into an estimate of the chance of scarring. It is common: in 15 to 30% of the population and in 35% of Dutch people aged 65 and over. The greater risk sits not in the liver but outside it: people with fatty liver have cardiovascular disease about 2 times as often and a 1.5 times higher mortality, because the same belly and the same insulin resistance also strain the vessels.
Which blood values show fatty liver?
Every value below has its own page with the reference ranges of four Dutch labs.
| Value | What it shows | Points here when |
|---|---|---|
| ALTdefining | The most specific liver value. Slightly raised, up to one and a half times the upper limit, often means nothing in someone who is otherwise well. | high |
| AST | Rises along, but also sits in muscle and heart. Its ratio to ALT helps read the cause. | high |
| Gamma-GT | Sensitive but unspecific: rises with almost any liver stimulus, alcohol and medication included. | high |
| FIB-4 | Estimates the chance of scarring from age, ALT, AST and platelets. Below 1.30 low, above 3.25 high. | high |
| Triglycerides | Where the fat comes from: a liver that sees too much insulin makes too many triglycerides. | high |
| HDL Cholesterol | Falls in the same pattern. With triglycerides, the metabolic side of the picture. | low |
| Fasting glucose | Fatty liver and insulin resistance go hand in hand; fasting glucose shows how far that has come. | high |
What are the symptoms of fatty liver?
These complaints are described for fatty liver in guidelines and research. None of them is exclusive to it: the same complaints fit many other explanations, and an abnormal value can exist without any of them.
Fatty liver is a chance finding. It gives no complaints and comes to light through a slightly raised ALT or through fat on an ultrasound made for another reason. Only when the liver becomes inflamed or forms scars can complaints follow, and even then by no means always. That is why this condition sits on this page among the pictures without complaints.
Often named, not confirmed
You will run into these links everywhere. We list them deliberately, with what the research does show.
- Fatiguenot confirmed
Often named, but the NHG states that fatty liver gives no complaints. Thuisarts describes tiredness only once the liver becomes inflamed, and even then not in everyone.
- Pain or a full feeling in the upper right abdomennot confirmed
According to Thuisarts this belongs to an inflamed liver, not to fat storage as such. No Dutch guideline describes a complaint for fatty liver without inflammation.
A complaint points in more than one direction, and a measurement explains no complaint: blood testing shows where your values stand, the reading and the diagnosis belong with your GP. The complaint list follows the Dutch GP guideline on viral hepatitis and other liver conditions (NHG) and Thuisarts.nl.
What causes fatty liver?
Metabolism
The fat in the liver is nearly always the fat of the rest of the body, by way of insulin.
- Excess weight, especially around the belly
- Type 2 diabetes or insulin resistance
- An abnormal fat profile: high triglycerides, low HDL
Alcohol and substances
The same picture with a different cause; the NHG deliberately keeps the two apart.
- Prolonged heavy drinking, which gives an alcoholic fatty liver and is reversible after stopping
- Some medicines, which the NHG names as a cause of steatosis
Age
The chance climbs with the years, even when the other causes do not change.
- At 65 and over, 35% of Dutch people have fatty liver, against 15 to 30% in the whole population
What is fatty liver confused with?
Each with the one value that tells the two apart.
Alcoholic fatty liver
The same fat on the ultrasound and the same slightly raised ALT. The distinction comes from the conversation about drinking, not from a value: gamma-GT rises in both.
Distinguishing value: Gamma-GT
Chronic hepatitis B or C
Also years of a slightly raised ALT without complaints. Only serology rules it out, and the NHG offers that test to people from countries where hepatitis is common even without complaints.
Distinguishing value: ALT
Haemochromatosis
Also a liver that suffers without you feeling it. A high ferritin with a high transferrin saturation points that way; in fatty liver, ferritin is at most slightly raised.
Distinguishing value: Ferritin
What you do about fatty liver
Take the fat out of the liver by taking it out of the belly. Losing weight is the only approach that is established to work: 5% less weight already removes most of the fat, 10% lets an inflamed liver recover too. That goes fastest by cutting soft drinks, fruit juice and sweets, because fructose is converted directly into liver fat, and by replacing white bread, biscuits and processed food with vegetables, legumes, whole grains, fish, nuts and olive oil. Coffee, two to three cups a day, demonstrably protects the liver. Drink no or hardly any alcohol, because the same liver also turns fatty from drinking, and two causes at once speed up scarring. Exercise daily and do strength training, because muscles take up glucose and lower the insulin that makes the liver produce fat; even without weight loss liver fat falls measurably from that. Sleep enough and keep an eye on your blood pressure and cholesterol, because the greatest risk with fatty liver sits in heart and vessels. Medicines that remove the liver fat itself hardly exist yet; what helps are the medicines for diabetes and excess weight that make the belly smaller. Measure again after three months: ALT falls within weeks once the liver is relieved, the triglycerides too, and the FIB-4 shows over years whether scars are being added. Scars that are already there do not disappear, and that is why the moment you start counts.
From which ALT does a lab call it high?
This is what the four largest Dutch labs publish themselves, side by side.
0 – 34U/L
Between 34 and 35 it depends on the lab, because each sets its limits on its own method and population. Above 35 every lab calls it abnormal.
every lab calls 0 – 34 U/L normal. Between 34 and 35 it depends on the lab.
Every age group per lab
| Lab | Group | Reference range |
|---|---|---|
| Unilabs(Saltro, Medlon, SHO, Atalmedial)2026 | Men 13–18 yrs | 0–31 U/L |
| Women 13–18 yrs | 0–29 U/L | |
| Men 19+ | 0–45 U/L | |
| Women 19+ | 0–34 U/L | |
| Star-shl2026 | Men | 0–45 U/L |
| Women | 0–34 U/L | |
| Certe2026 | Men 18+ | < 45 U/L |
| Women 18+ | < 34 U/L | |
| Clinical Diagnostics2026 | Men | < 50 U/L |
| Women | < 35 U/L |
How to get fatty liver measured
- Fasting
- Fasting, if you want to read the fats and fasting glucose alongside, and that is the point here. The liver values themselves do not care about food.
- Material
- Venous blood, drawn at one of our collection points.
- Results
- Results within 24 hours of analysis, in the app.
- Referral
- No referral from a GP required.
- Which test
- The comprehensive test (€229, single test) measures the values on this page.
- Where to draw
- You can draw at 250+ locations near you, no referral needed. See the locations
Frequently asked questions
What are the symptoms of fatty liver?
None. Fatty liver gives no complaints and is usually found by chance: a slightly raised ALT in a blood test done for another reason, or fat on an ultrasound of the abdomen. Tiredness, nausea or pain in the upper right of the abdomen only belong with a liver that becomes inflamed, and even then not in everyone. What you do see is the belly: a growing waist is the sign you have without a blood test.
From which ALT is it fatty liver?
There is no ALT that proves fatty liver; the diagnosis falls by exclusion, after alcohol, medication and viral hepatitis have been crossed off, usually with an ultrasound. There is a limit where further work-up begins: from one and a half times the upper limit, so 68 U/L on a report that uses 45, the test is repeated after about four weeks. Below that a rise in someone without complaints often has no meaning, and losing weight is all that is needed.
Is fatty liver dangerous?
For the liver itself usually not directly: the fat as such is reversible. In a small share the liver becomes inflamed and can form scars over time, and the FIB-4 estimates that chance. The greater risk sits outside the liver: people with fatty liver have cardiovascular disease about 2 times as often and a 1.5 times higher mortality, because the same belly and the same insulin resistance strain the vessels. That is why blood pressure belongs with it, and cholesterol.
What does the FIB-4 say in fatty liver?
The FIB-4 is a score from age, ALT, AST and platelets that estimates the chance of advanced scarring, without ultrasound or biopsy. Below 1.30 that chance counts as low and lifestyle is the whole treatment, above 3.25 as high and then the liver should be imaged, and the band in between deliberately says nothing decisive. It is an estimate of a pattern, not a diagnosis, and precisely for that reason useful as a first sieve.
Can fatty liver disappear again?
Yes, the fat as such can, and that is the reason to know it. Anyone who loses 5 to 10% of their weight sees the liver fat largely disappear and ALT fall within weeks; cutting soft drinks, less alcohol, exercise and strength training do the work, and at the same time lower the risk of cardiovascular disease and diabetes. Scar tissue that has already formed does not disappear, and that is why the moment you start counts.
Sources
- 1.NHG-Standaard Virushepatitis en andere leveraandoeningen. 2023. richtlijnen.nhg.org
- 2.EASL-EASD-EASO Clinical Practice Guidelines on the management of metabolic dysfunction-associated steatotic liver disease (MASLD), Journal of Hepatology. 2024. doi.org
- 3.Thuisarts.nl, Ik heb een vetlever. 2023. thuisarts.nl
This page explains what a result means. It is not a diagnosis and not treatment advice. Discuss complaints or an abnormal value with your doctor.
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