Fibrosis is the replacement of normal liver tissue with scar (connective) tissue. It is the liver's universal response to any prolonged injury: fatty liver disease, viral hepatitis, alcohol, autoimmune processes.
Fibrosis is the main prognostic factor in any chronic liver disease. Not the amount of fat and not the enzyme level, but the fibrosis stage determines how it will end.
Reference ranges
Stages on the METAVIR scale:
| F0 | no fibrosis |
| F1 | portal fibrosis without septa |
| F2 | fibrosis with a few septa (significant) |
| F3 | many septa without cirrhosis (advanced) |
| F4 | cirrhosis |
What an elevated level means
Fibrosis progression is asymptomatic for a long time — the liver does not hurt. Complaints (weakness, heaviness in the right upper abdomen) are non-specific and appear late.
At the cirrhosis stage (F4) complications appear: portal hypertension, ascites, esophageal varices, hepatic encephalopathy, and a sharply rising risk of liver cancer.
What accelerates fibrosis: type 2 diabetes, obesity, alcohol, age over 50, male sex, concurrent viral hepatitis.
What a low level means
F0–F1 means no fibrosis or minimal fibrosis. This is a favorable stage at which it is enough to remove the cause of the injury and monitor.
An encouraging fact: fibrosis is reversible. When the cause is removed (weight loss in NAFLD, quitting alcohol, treating hepatitis), scar tissue can partially resolve — and this has been shown even for advanced stages. As a rule, only established cirrhosis is irreversible.
How the test is done
The "gold standard" is a biopsy, but it is invasive and not used for screening.
Today a two-step non-invasive strategy is used. Step 1: calculated indices from ordinary tests — FIB-4 and NFS (age, ALT, AST, platelets, albumin). They are good at ruling out advanced fibrosis. Step 2: if the index is suspicious — elastography (FibroScan), which measures liver stiffness.
Important: normal ALT and AST do not rule out fibrosis.
What affects the value
- The cause of the injury — NAFLD, alcohol, viral hepatitis, autoimmune disease.
- Type 2 diabetes — the strongest accelerator of fibrosis in NAFLD.
- Alcohol — accelerates fibrosis with any underlying cause.
- Age — the risk of significant fibrosis rises after 50.
- Obesity — both general and especially visceral.
- Weight loss — able to partially reverse fibrosis.
Calculate using this marker
Calculators where Liver fibrosis is used directly:
Frequently asked questions
Is liver fibrosis reversible?
Yes — and this is the most important good news. When the cause is removed (weight loss, quitting alcohol, treating hepatitis), scar tissue can partially resolve, even at advanced stages. As a rule, only established cirrhosis is irreversible.
How do you find the fibrosis stage without a biopsy?
Start with calculated indices from ordinary tests — FIB-4 and NFS. They reliably rule out advanced fibrosis in most people. If the result is suspicious, the next step is elastography (FibroScan), and a biopsy is needed only in ambiguous cases.
My liver function tests are normal — is there definitely no fibrosis?
No, that is not a guarantee. ALT and AST often stay normal even with marked fibrosis, especially in NAFLD. That is exactly why risk should be assessed with indices (FIB-4, NFS), not enzymes alone.