Silent liver disease (MASLD): signs your liver is under strain

Most men with silent liver disease do not know they have it. MASLD, metabolic dysfunction-associated steatotic liver disease, is fat building up in the liver as part of a wider metabolic problem. It was called non-alcoholic fatty liver disease (NAFLD) until 2023, and the NHS still lists it under that name. [1]

In its early stages it does not usually cause any symptoms, which is where the word "silent" comes from. [1]

This article explains what MASLD is and why men are more exposed. It covers which signs eventually appear, how the condition is diagnosed in the UK, and why a routine blood test is often the first place it shows up.

What is MASLD and why does the name matter?

MASLD is diagnosed when there is fat in the liver (steatosis) plus at least one of five cardiometabolic risk factors, meaning measures of heart and metabolic health. The 2023 international consensus that renamed the condition defined it this way on purpose. The old name described what the condition was not (not alcohol); the new one names what drives it. [2]

The five criteria, with the adult thresholds in the 2024 European guideline, are: [3]

• a BMI (body mass index) of 25 or more, or a waist of 94 cm or more for men (80 cm for women) of European origin;
• raised blood sugar: an HbA1c (3-month average blood sugar) of 39 mmol/mol or more, a fasting glucose of 5.6 mmol/L or more, type 2 diabetes, or treatment for it;
• triglycerides of 1.7 mmol/L or more, or treatment for them;
• HDL cholesterol of 1.0 mmol/L or less for men (1.3 for women), or treatment for it;
• blood pressure of 130/85 mmHg or more, or treatment for it.

The condition sits on a spectrum. At the mild end is simple fatty liver. In a minority it progresses to metabolic dysfunction-associated steatohepatitis (MASH), where the fat is accompanied by inflammation, then to fibrosis (scarring), cirrhosis and in some cases liver cancer. [4]

People who also drink above low-risk levels fall into a separate category, MetALD (MASLD with increased alcohol intake). [2]

How common is silent liver disease in men?

Silent liver disease is common: Liver UK estimates that about 1 in 4 adults in the UK have MASLD. [5] NICE puts the population figure at between 20% and 30%. [4]

Globally, the Global Burden of Disease study estimated that about 1.3 billion people, 16% of the world's population, were living with MASLD in 2023, and projects 1.8 billion by 2050. [6] A separate review of adult studies put prevalence at about 30% of adults worldwide; the two figures use different methods and populations, which is why they differ. [7]

Men are more affected. A pooled analysis of 54 studies found women had a 19% lower risk of the condition than men. [8] Prevalence in men peaks between 45 and 49. [9]

One reason is fat distribution: men store proportionally more fat inside the abdomen, around the liver and intestines, than women do at the same BMI. [10] See Visceral fat in men for the mechanism.

The caveat is that once the disease is present, women, especially over 50, are more likely to reach advanced scarring. [8]

Why does MASLD cause no symptoms early on?

Fat accumulating inside liver cells does not, on its own, produce anything you can feel. Liver UK puts it plainly: most people have no symptoms in the early stages, and it is common to have the condition for years without noticing. [5]

NICE records that in most people MASLD is only detected incidentally, when liver blood tests or an abdominal scan are done for another reason. [4] The markers most often involved are the liver enzymes ALT, AST and GGT, which rise when liver cells are under strain. [11] Even then, the enzymes are an imperfect flag, as the diagnosis section below explains.

What are the warning signs of liver strain?

The NHS says most people have no symptoms. Some have feeling very tired, feeling generally unwell, or pain or discomfort in the tummy under the right ribs. [1] By the time the liver is scarred, the NHS cirrhosis page adds these: [12]

• Feeling tired or unwell all the time
• Loss of appetite, or losing weight without trying
• Tummy pain
• Visible small blood vessels on the skin, and blotchy red palms
• Yellow skin or whites of the eyes (jaundice)
• A swollen tummy, legs, ankles or feet from fluid build-up
• Itchy skin, and in late disease vomiting blood or black stools

None of these is an early sign, which is why the condition is usually found by chance rather than by feeling unwell.

What puts men at higher risk?

MASLD does not develop at random. The NHS lists the factors it is linked to: being overweight, particularly with fat around the stomach and waist; type 2 diabetes; high blood pressure; high cholesterol. [1] Its list also includes an unhealthy diet, physical inactivity and being over 50. [1]

The research behind some of these:

• Visceral fat. Fat stored inside the abdomen drains into the portal vein, the vessel that feeds the liver, so the fatty acids and inflammatory signals it releases reach the liver first. How much of the harm comes by that route is still debated, but the association with liver fat is consistent. [10]
• Insulin resistance and raised blood sugar. When the body's cells respond less well to insulin, the liver stores more fat and makes more of it. Type 2 diabetes is on both the NHS list and the five diagnostic criteria. [3]
• Sugary drinks. In a 7-week trial in 94 men, drinks sweetened with fructose or table sugar doubled the rate at which the liver made new fat, while glucose-sweetened drinks did not. [13] The liver handles fructose differently and turns more of it into fat.
• Sitting. In a Korean study of 139,056 adults, sitting for 10 or more hours a day was associated with a 9% higher prevalence of fatty liver, independent of exercise. [14] The European guideline says a sedentary lifestyle increases the risk and recommends minimising sitting time. [3]
• Sleep apnoea. A pooled analysis of 9 studies found obstructive sleep apnoea independently associated with the development and progression of fatty liver. [15] This is an association; the two share visceral fat as a driver. See Sleep apnoea and weight gain.

The more of these you carry, the greater the load on the liver. MASLD rarely exists alone; it tends to sit alongside the other markers of metabolic dysfunction described in Metabolic syndrome in men.

How is MASLD diagnosed in the UK?

MASLD is not diagnosed by a blood test alone. Liver blood tests cannot diagnose or rule out MASLD on their own. [5] NICE goes further: more than 80% of people with MASLD have normal routine liver blood tests, so its guideline says do not use them to rule the condition out. [4]

The usual UK pathway, set out by the British Society of Gastroenterology and NICE, runs in stages. [16] [4]

• Imaging, usually an ultrasound scan, shows fat in the liver.
• A fibrosis score such as FIB-4, calculated from age, ALT, AST and platelet count, sorts people into low, indeterminate and high risk of scarring. In the European guideline, below 1.3 is low risk and above 2.67 is high. [3]
• A specialist blood test or scan for those not clearly low risk. NICE recommends the ELF (enhanced liver fibrosis) test, diagnosing advanced fibrosis at a score of 10.51 or above, with a retest every 3 years for those below it. [4] The BSG guideline lists a FibroScan, a type of ultrasound that measures liver stiffness, as a second-line alternative. [16]
• Liver biopsy is reserved for uncertain cases; the European guideline says it is not required in most. [3]

Clinical context matters as much as any single result. Normal enzymes in a man with a large waist, raised HbA1c and high triglycerides do not close the question.

Can MASLD improve?

In its earlier stages the evidence says it can improve, and sometimes reverse. The NHS says that unless the condition has progressed, no treatment beyond healthy lifestyle change is needed. [1] That means a balanced diet, at least 150 minutes of exercise a week, and losing weight if you are overweight. [1]

Liver UK says losing 5% to 10% of body weight can help control the condition and may reverse some liver damage. [5]

The trial evidence is specific about how much. In a 52-week study of 293 people with MASH, everyone who lost 10% or more of their body weight improved on the disease activity score, a measure of fat, inflammation and cell damage in the liver. [17] Of that group, 90% had their steatohepatitis resolve and 45% had their fibrosis regress. With a loss of 5% or more, 58% saw their steatohepatitis resolve. [17]

The European guideline turns that into targets. It recommends a sustained loss of 5% or more to reduce liver fat, 7% to 10% to improve inflammation, and 10% or more to improve fibrosis. [3]

Those are population results from trials, not a prediction for any one man. The NHS says that once there is scarring, specialist care is needed alongside lifestyle change, [1] which is the argument for finding the condition early.

Most people never reach that point. Of 100 people with early MASLD, Liver UK estimates 10 to 30 go on to develop advanced scarring and 70 to 90 do not. [5]

Where do liver blood markers fit in?

Symptoms arrive late, so the practical check is a blood test. Liver enzymes sit alongside the metabolic markers that drive the condition: blood sugar, triglycerides and HDL.

A raised ALT, AST or GGT is a signal worth investigating with your GP. That holds even for a modest rise. ALT rises with liver inflammation, and moderately with high alcohol intake, diabetes or raised triglycerides, all of which can cause fatty liver. [11]

GGT rises with alcohol and some medicines as well as liver fat. [11] A normal set does not clear the liver, for the reasons above.

HeMed's at-home blood test measures 10 markers, and 3 of them are liver enzymes: ALT, AST and GGT. The same panel includes HbA1c, triglycerides and HDL cholesterol, markers that also appear in the cardiometabolic risk factors described above. Every result is reviewed by your clinical team, and a retest every 6 months shows whether the numbers are moving.

A blood test alone does not diagnose or stage liver disease, and normal liver blood tests do not rule the condition out. Out-of-range results are a reason to speak to your GP, who may arrange scans and further tests. HeMed does not diagnose or treat liver disease.

When should you see a GP?

See your GP promptly if you have any of the following:

• pain or a dull ache under your right ribs that does not go away;
• yellowing of the skin or the whites of the eyes;
• unexplained weight loss, or persistent tiredness with no clear cause;
• swelling in your tummy, legs or ankles;
• a blood test result showing raised ALT, AST or GGT.

Even without symptoms, raise liver health with your GP if you carry several of the risk factors above. That means a waist of 94 cm or more, raised blood sugar, raised triglycerides, high blood pressure or type 2 diabetes.

The NHS says to see a GP if you think you might have cirrhosis, and to seek urgent help for vomiting blood or black, tarry stools. [12] The condition summary is on Silent liver disease (MASLD): what to know.

Frequently asked questions

What does MASLD stand for?

Metabolic dysfunction-associated steatotic liver disease. It replaced the name non-alcoholic fatty liver disease (NAFLD) in 2023, after an international consensus found the old terms stigmatising and inaccurate about the cause.

The new definition requires fat in the liver plus at least one cardiometabolic risk factor.

Can you have MASLD if you do not drink alcohol?

Yes. MASLD is driven by metabolic factors: visceral fat, insulin resistance, raised blood sugar and blood fats. Alcohol is not part of the definition.

People who have those factors and also drink above low-risk levels are classed separately, as MetALD.

Which blood tests show liver strain?

The liver enzymes ALT, AST and GGT. They are released into the blood when liver cells are under stress and are part of a standard liver blood test.

They can be normal in MASLD: NICE records that more than 80% of people with the condition have normal routine liver blood tests, so they cannot rule it out.

Is MASLD the same as cirrhosis?

No. MASLD is a spectrum: simple fatty liver sits at the mild end, and Liver UK says this stage can improve with lifestyle change. Cirrhosis is advanced scarring at the far end.

Most people with MASLD never reach cirrhosis: Liver UK estimates 10 to 30 of every 100 with early disease develop advanced scarring.

How does HeMed relate to liver health?

HeMed provides clinician-led weight management. Its at-home blood test measures 10 markers, 3 of which are liver enzymes (ALT, AST and GGT). Every result is reviewed by your clinical team, with a retest every 6 months.

A blood test alone does not diagnose or stage liver disease, and HeMed does not diagnose or treat it. Out-of-range results are a reason to speak to your GP.

Why are men more affected by MASLD than women?

Men store more fat inside the abdomen at the same BMI, and that fat drains into the vein that feeds the liver. A pooled analysis found women had a 19% lower risk of the condition.

Women who do have it, especially over 50, are more likely to reach advanced scarring. The sex difference is in who gets it, not in how serious it can become.

Can losing weight improve MASLD?

In the earlier stages, yes. The NHS names weight loss as part of healthy lifestyle change, the main treatment. The European guideline sets targets of 5% or more to reduce liver fat, 7% to 10% to improve inflammation and 10% or more to improve scarring.

In a 52-week study, 90% of people who lost 10% or more of their weight had their steatohepatitis resolve. These are population figures from a trial.

HeMed provides clinician-led weight management. We do not diagnose or treat silent liver disease (MASLD). This page is general health information, not medical advice. If you are worried about symptoms, speak to your GP, or use NHS 111.

Next step: see what the HeMed blood test measures.

Sources (17)

1. NHS, "Non-alcoholic fatty liver disease (NAFLD)", page last reviewed 31 July 2025: also known as MASLD; it "does not usually cause any symptoms"; most people only have the first stage; the symptoms some people have; linked factors; "apart from making healthy lifestyle changes you will not need any other treatment unless your condition has progressed". nhs.uk/conditions/non-alcoholic-fatty-liver-disease. Accessed 8 October 2026.
2. Rinella ME and colleagues. "A multisociety Delphi consensus statement on new fatty liver disease nomenclature." Hepatology 2023;78(6):1966 to 1986 (MASLD defined as steatosis with at least 1 of 5 cardiometabolic risk factors; MetALD for 140 to 350 g a week of alcohol in women and 210 to 420 g in men). doi.org/10.1097/HEP.0000000000000520. Accessed 8 October 2026.
3. European Association for the Study of the Liver, European Association for the Study of Diabetes and European Association for the Study of Obesity. "EASL-EASD-EASO Clinical Practice Guidelines on the management of metabolic dysfunction-associated steatotic liver disease (MASLD)." Journal of Hepatology 2024;81(3):492 to 542 (Table 3 cardiometabolic criteria; FIB-4 cut-offs; weight loss targets; sedentary lifestyle; biopsy rarely required). doi.org/10.1016/j.jhep.2024.04.031. Accessed 8 October 2026.
4. NICE, "Metabolic dysfunction-associated steatotic liver disease (MASLD): assessment and management", NG49, published 6 July 2016, last updated 31 July 2026: prevalence "between 20 and 30% of the population"; "more than 80% of patients with MASLD have normal routine liver blood tests"; recommendation 1.1.3 "Do not use routine liver blood tests to rule out MASLD"; ELF score of 10.51 or above for advanced fibrosis, retest every 3 years below it; MASH "develops in only a minority". nice.org.uk/guidance/ng49. Accessed 8 October 2026.
5. Liver UK (formerly the British Liver Trust), "MASLD" and its symptoms, diagnosis, stages and treatment pages, last reviewed July 2026: "about 1 in 4 adults in the UK"; most people have no symptoms early on; "a liver blood test cannot diagnose or rule out MASLD on its own"; of 100 people with early MASLD, 10 to 30 develop advanced scarring; "losing 5% to 10% of your body weight can help control the condition and may reverse some liver damage". liveruk.org/about-liver-disease/conditions/masld. Accessed 8 October 2026.
6. GBD 2023 MASLD Collaborators. "Global burden of metabolic dysfunction-associated steatotic liver disease, 1990 to 2023, and projections to 2050." Lancet Gastroenterology and Hepatology 2026;11(6):463 to 494. doi.org/10.1016/S2468-1253(26)00011-7. Accessed 8 October 2026.
7. Younossi ZM and colleagues. "The global epidemiology of nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH): a systematic review." Hepatology 2023;77(4):1335 to 1347 (pooled adult prevalence 30.05%). doi.org/10.1097/HEP.0000000000000004. Accessed 8 October 2026.
8. Balakrishnan M and colleagues. "Women have a lower risk of nonalcoholic fatty liver disease but a higher risk of progression vs men: a systematic review and meta-analysis." Clinical Gastroenterology and Hepatology 2021;19(1):61 to 71. doi.org/10.1016/j.cgh.2020.04.067. Accessed 8 October 2026.
9. Feng G and colleagues. "Global burden of metabolic dysfunction-associated steatotic liver disease, 2010 to 2021." JHEP Reports 2025;7(3):101271 ("Prevalence peaked at ages 45-49 for men and 50-54 for women"). doi.org/10.1016/j.jhepr.2024.101271. Accessed 8 October 2026.
10. Schorr M and colleagues. "Sex differences in body composition and association with cardiometabolic risk." Biology of Sex Differences 2018;9:28. doi.org/10.1186/s13293-018-0189-3; Tchernof A, Després JP. "Pathophysiology of human visceral obesity: an update." Physiological Reviews 2013;93(1):359 to 404. doi.org/10.1152/physrev.00033.2011. Accessed 8 October 2026.
11. Association for Laboratory Medicine, Lab Tests Online UK, "Alanine aminotransferase (ALT) test", "Aspartate aminotransferase (AST) test" and "Gamma-glutamyl transferase (GGT) test": ALT "A moderately high ALT can also occur when there is a high alcohol intake, diabetes or raised serum triglycerides, all of which can cause fatty liver"; raised GGT "may indicate that something is going on with your liver, but not specifically what". labtestsonline.org.uk. Accessed 8 October 2026.
12. NHS, "Cirrhosis: symptoms", page last reviewed 10 February 2025. nhs.uk/conditions/cirrhosis/symptoms. Accessed 8 October 2026.
13. Geidl-Flueck B and colleagues. "Fructose- and sucrose- but not glucose-sweetened beverages promote hepatic de novo lipogenesis: a randomized controlled trial." Journal of Hepatology 2021;75(1):46 to 54. doi.org/10.1016/j.jhep.2021.02.027. Accessed 8 October 2026.
14. Ryu S and colleagues. "Relationship of sitting time and physical activity with non-alcoholic fatty liver disease." Journal of Hepatology 2015;63(5):1229 to 1237 (prevalence ratio 1.09, 95% CI 1.06 to 1.11, for 10 or more hours of sitting a day). doi.org/10.1016/j.jhep.2015.07.010. Accessed 8 October 2026.
15. Jin S, Jiang S, Hu A. "Association between obstructive sleep apnea and non-alcoholic fatty liver disease: a systematic review and meta-analysis." Sleep and Breathing 2018;22(3):841 to 851. doi.org/10.1007/s11325-018-1625-7. Accessed 8 October 2026.
16. Newsome PN and colleagues. "Guidelines on the management of abnormal liver blood tests." British Society of Gastroenterology. Gut 2018;67(1):6 to 19 (FIB-4 or NAFLD fibrosis score first line; ELF or FibroScan second line). doi.org/10.1136/gutjnl-2017-314924. Accessed 8 October 2026.
17. Vilar-Gomez E and colleagues. "Weight loss through lifestyle modification significantly reduces features of nonalcoholic steatohepatitis." Gastroenterology 2015;149(2):367 to 378 (293 patients, 52 weeks: with 10% or more weight loss, 90% NASH resolution and 45% fibrosis regression; 58% resolution with 5% or more). doi.org/10.1053/j.gastro.2015.04.005. Accessed 8 October 2026.

Numbered markers in the page text link to these entries. Statistics describe populations, not any one person’s results.