NAFLD is the accumulation of fat in more than 5% of liver cells in people who do not abuse alcohol. Today it is the most common liver disease in the world: about a quarter of the adult population is affected.
The modern name is MAFLD (metabolic-associated), and it more accurately reflects the essence: this is not a liver disease "in itself" but the hepatic manifestation of insulin resistance and metabolic syndrome.
Reference ranges
The stages of the disease — from reversible to irreversible:
| 1. Steatosis | fat in the liver, no inflammation — reversible |
| 2. Steatohepatitis (NASH) | fat + inflammation and cell damage |
| 3. Fibrosis | growth of scar tissue (stages F1–F3) |
| 4. Cirrhosis (F4) | irreversible remodeling of the liver |
What an elevated level means
Here "elevation" means progression through the stages. The danger of NAFLD lies in its lack of symptoms: for years a person feels nothing while the liver travels from steatosis to fibrosis.
The main risk is not only cirrhosis and liver cancer. People with NAFLD more often die of cardiovascular events than of liver ones: the disease marks a generally unfavorable metabolic background.
Risk factors: visceral obesity, insulin resistance, type 2 diabetes, high triglycerides, low HDL.
What a low level means
The absence of steatosis is a healthy liver. An important and encouraging feature of NAFLD: in the early stages it is fully reversible.
Losing 7–10% of body weight can remove not only the fat from the liver but also the inflammation, and in some cases partially reverse fibrosis. The liver has an outstanding capacity to recover if the cause is removed.
How the test is done
It can be suspected via ultrasound (which sees steatosis) and elevated ALT/AST — but normal enzymes do not rule out the disease; they are often normal even with marked fibrosis.
The modern approach is non-invasive calculated indices: FLI and HSI to assess steatosis, FIB-4 and NFS to assess fibrosis risk. They are computed from ordinary tests and help screen out those who need elastography or a biopsy.
What affects the value
- Visceral fat and insulin resistance — the root cause.
- Fructose and sugar — the liver converts fructose directly into fat.
- Physical inactivity — exercise reduces liver fat even without weight loss.
- Type 2 diabetes — sharply accelerates fibrosis progression.
- Rapid weight loss — paradoxically can worsen the condition; weight should be lost gradually.
- Alcohol — even moderate amounts accelerate damage on a background of NAFLD.
Calculate using this marker
Calculators where NAFLD / MAFLD is used directly:
Frequently asked questions
My ultrasound shows fatty liver — is that dangerous?
Steatosis by itself (fat without inflammation) is a reversible stage and not directly dangerous. The danger is where it is heading. The main thing is to assess fibrosis risk (for example, with the FIB-4 index): it is fibrosis, not fat, that determines the prognosis.
My ALT and AST are normal — does that mean my liver is healthy?
Unfortunately, no. This is one of the most dangerous misconceptions in NAFLD: the enzymes often stay normal even with marked fibrosis. That is why calculated indices (FIB-4, NFS) are used, not just ALT/AST.
Is there a pill for fatty liver disease?
There is no universal drug. What works, proven, is weight loss: minus 5% removes the fat, minus 7–10% the inflammation, and in some cases partially reverses fibrosis. Plus cutting sugar and fructose, regular exercise and blood-sugar control.