Health condition
Non-alcoholic steatohepatitis
Non-alcoholic steatohepatitis (NASH/MASH) is the aggressive form of fatty liver disease, where fat is accompanied by inflammation and liver cell damage that can scar the liver.
Why trust this guide
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Editorial team
Written by our editorial team from the UK sources listed on each page.
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Sourced from guidance
Checked against current NHS and UK specialist society guidance at the time of review.
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Current for 2026
Reviewed on 2026-09-27 with the next review scheduled for 2027-09-27.
Key facts
The essentials at a glance.
The symptoms to recognise, when to seek help, which specialist to see, and what treatment usually involves.
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Usually few symptoms; tiredness and vague right-sided discomfort are common
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See your GP if you have fatty liver with persistently raised liver enzymes
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Specialist: a consultant hepatologist stages the disease and monitors fibrosis
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Treatment options include supervised weight loss, diabetes drugs with liver benefit, and clinical trials
Understanding the condition
What it is and what happens next.
What causes it, how it is diagnosed, and the treatment routes available in the UK.
What it is and how it feels
Non-alcoholic steatohepatitis, increasingly called MASH, is fatty liver disease with active inflammation. Unlike simple fatty liver, ongoing liver cell injury drives fibrosis, and over years a proportion of people progress towards cirrhosis. It is strongly associated with type 2 diabetes and central weight gain.
Diagnosis and treatment routes
Diagnosis combines blood tests, FibroScan and sometimes liver biopsy to grade inflammation and stage scarring. Weight loss of 7-10% can resolve steatohepatitis; hepatologists may also use newer licensed therapies or trial medication in suitable patients and monitor fibrosis over time. In many parts of the UK, routine NHS referrals for this kind of problem currently take 20-45+ weeks, whereas an initial appointment with a private consultant is typically available within around two weeks.
Seeing a specialist
Who to see, and how quickly you can be seen.
The specialist for this condition is usually a consultant hepatologist. Your GP can refer you on the NHS, or you can arrange a private consultation directly.
A quiet reminder
This guide is for information, not medical advice.
Your GP knows your history and can tell you which parts apply to you. If in doubt, see them - and seek urgent care for any of the emergency symptoms described above.
Frequently asked
Common questions about Non-alcoholic steatohepatitis.
Quick, plain-English answers to what people ask us most.
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What is non-alcoholic steatohepatitis (NASH)?
Non-alcoholic steatohepatitis is a more advanced, inflammatory form of non-alcoholic fatty liver disease, in which excess liver fat is accompanied by liver cell damage and inflammation, which can progress to scarring over time.
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What causes NASH?
NASH is strongly linked to obesity, insulin resistance, type 2 diabetes and high cholesterol, with the same risk factors that cause simple fatty liver progressing to cause active inflammation and cell damage in NASH.
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What are the symptoms of NASH?
Many people have no symptoms, particularly in earlier stages, with NASH often found through abnormal liver blood tests or imaging, though fatigue and discomfort in the upper right abdomen can occur as it progresses.
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Is NASH dangerous?
Yes, unlike simple fatty liver, NASH involves active liver damage and can progress to significant liver scarring, cirrhosis, and increased risk of liver cancer if not addressed.
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Can NASH be reversed?
Yes, particularly in earlier stages, significant weight loss, dietary changes and increased physical activity can meaningfully reduce liver inflammation and even improve early scarring in many people.
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How is NASH treated?
Treatment centres on lifestyle changes including gradual weight loss, improved diet and regular exercise, with newer specific medications now becoming available for more advanced NASH, alongside management of associated diabetes and cholesterol.
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When should I see a hepatologist about suspected NASH, and how quickly can I be seen privately?
See a hepatologist if you have risk factors like obesity or diabetes with abnormal liver blood tests or imaging findings. A private hepatologist can typically arrange assessment within about two weeks.