What is liver fibrosis?

Liver fibrosis develops when scar tissue accumulates in the liver as a result of ongoing or repeated injury or inflammation. Nearly all forms of chronic liver disease can eventually lead to fibrosis¹

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Liselotte Schjerning, Denmark, living with MASH

What is the impact of fibrosis on the liver?

The scar tissue that develops with MASH cannot repair itself or function properly, unlike the healthy liver cells. As a consequence, fibrosis can disrupt the normal structure and function of the liver, including the liver's ability to regenerate².

Additionally, scar tissue from fibrosis can obstruct or restrict blood flow within the liver, depriving healthy liver cells of nutrients, which can lead to the formation of even more scar tissue. If fibrosis progresses to cirrhosis, liver damage may be irreversible³.

Diagnosis of liver fibrosis

Blood Tests 
Blood tests can be used to determine the level of scarring or fibrosis and help distinguish between the severity of the disease². Two common blood-tests used is the FIB-4⁵, which is used to assess the risk of advanced MASH and the ELF test⁴, which is used to assess the level of clinically significant fibrosis.

Image Tests
Transient elastography⁶ is a special type of ultrasound, that is used to measure liver stiffness. Stiffness is a typical sign of scarring or fibrosis caused by MASH.

Liver Biopsy 
In some cases a liver biopsy may be required to determine the level of scarring. It is an invasive procedure associated with complications in 1–3% of cases².

What are the stages of liver fibrosis?

MASLD, marked by excess fat in the liver, can develop into MASH, where liver cells become damaged.

Over time, this can lead to fibrosis (scarring), known as MASH with fibrosis. The most severe stage is cirrhosis, characterized by extensive scarring.

MASH with no/mild fibrosis 
This is the early stage where there is excess fat in the liver, inflammation and cell injury.

MASH with moderate fibrosis 
At this stage, there is more noticeable scarring in the liver.

MASH with advanced fibrosis 
Here, the scarring in the liver is significant. The liver's ability to function is more affected.

Cirrhosis 
This is the most severe stage, where the liver is heavily scarred.

MASH and MASLD are updated terms for conditions previously known as NASH (non-alcoholic steatohepatitis) and NAFLD (non- alcoholic fatty liver disease). Similarly, "steatotic liver disease" is the current term for what was once called "fatty liver disease".

Ramón Bataller, Liver fibrosis: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC546435/ Last accessed: September 2024
Clémence M. Canivet, Screening for Liver Fibrosis in the General Population: Where Do We Stand in 2022: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9818643/ Last accessed: July 2024
O'Hara J, Cost of non-alcoholic steatohepatitis in Europe and the USA: The GAIN study: https://pmc.ncbi.nlm.nih.gov/articles/PMC7397699/  Last accessed: May 2025
James W Day, The enhanced liver fibrosis (ELF) test in diagnosis and management of liver fibrosis:  https://pubmed.ncbi.nlm.nih.gov/30526098/ Last accessed: July 2024
Albert Blanco-Grau, Assessing Liver Fibrosis Using the FIB4 Index in the Community Setting:  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8700445/ Last accessed: August 2024
Rosa M.S. Sigrist, Ultrasound Elastography: Review of Techniques and Clinical Applications: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5399595/ Last accessed: September 2024

What is cirrhosis and how is it related to MASH?

While MASH often progresses slowly, it can lead to cirrhosis, impacting the liver function.

Is there a connection between Type 2 Diabetes and MASH?

Understand the link between Type 2 Diabetes and liver disease to improve your health management.

What is the difference between MASLD and MASH?

MASH is an advanced form of MASLD. 20% of people living with MASLD progress to MASH.