Is Sauna Good for Fatty Liver? Evidence & Risks

Is sauna good for fatty liver? It is a question many people ask as interest in heat therapy grows alongside rising rates of metabolic liver disease. Fatty liver disease, particularly metabolic dysfunction-associated steatotic liver disease (MASLD), affects a significant proportion of UK adults and is primarily managed through lifestyle change. While sauna use has attracted attention for its cardiovascular and metabolic effects, understanding what the current evidence actually shows, and what risks may apply to people with liver disease, is essential before incorporating it into any health routine.

What is fatty liver disease and how does it develop?

Fatty liver disease (MASLD) develops when excess fat accumulates in liver cells, driven by obesity, insulin resistance, poor diet, and physical inactivity. Without intervention it can progress to inflammation, fibrosis, and cirrhosis.

Fatty liver disease is a condition in which excess fat accumulates within liver cells, impairing normal liver function over time. It is broadly divided into two main types: metabolic dysfunction-associated steatotic liver disease (MASLD, previously called non-alcoholic fatty liver disease or NAFLD) and alcohol-related liver disease (ALD). MASLD is the term increasingly adopted in UK and international clinical practice following a 2023 international consensus, though many NHS and NICE resources, including NICE guideline NG49, continue to use NAFLD. Both terms refer to the same condition and patients may encounter either.

MASLD develops when the liver processes more fat than it can efficiently export or break down. Key contributing factors include:

• Obesity and excess visceral fat, particularly around the abdomen

• Type 2 diabetes and insulin resistance

• High triglyceride or low HDL cholesterol levels

• A diet high in refined carbohydrates and ultra-processed foods

• Physical inactivity

Alcohol-related fatty liver results directly from the liver metabolising ethanol, which disrupts normal fat metabolism and promotes fat deposition.

In many people, fatty liver causes no symptoms and is discovered incidentally during an ultrasound or blood test. However, without intervention, MASLD can progress through stages of increasing inflammation (metabolic-associated steatohepatitis, or MASH), fibrosis, cirrhosis, and in some cases liver failure or hepatocellular carcinoma. NICE NG49 highlights that early identification and lifestyle modification are central to preventing disease progression.

In UK primary care, initial assessment typically includes liver function tests (LFTs), exclusion of other causes of liver disease, and ultrasound where clinically indicated. Non-invasive fibrosis scoring using the FIB-4 index or NAFLD Fibrosis Score (NFS) is used to stratify risk; where results are indeterminate or high, the Enhanced Liver Fibrosis (ELF) test or referral to hepatology may be considered, in line with NICE NG49. Understanding how fatty liver develops and is assessed is important context for evaluating whether interventions such as sauna use could play any supportive role.

Can using a sauna actually help with fatty liver?

Sauna use is not recommended by NICE or the NHS as a treatment for fatty liver disease. Indirect metabolic benefits are plausible but unproven in liver-specific clinical trials.

There is currently no robust clinical evidence that sauna use directly treats or reverses fatty liver disease. It is not recommended by NICE (NG49), the NHS, or any UK liver health guideline as a therapeutic intervention for this condition, and it is not a substitute for the lifestyle changes that form the cornerstone of MASLD management.

That said, there are plausible indirect mechanisms through which regular sauna bathing might offer modest supportive benefits alongside established treatments:

• Cardiovascular and metabolic effects: Repeated passive heat exposure has been associated in some observational studies with improvements in cardiovascular function, blood pressure, and insulin sensitivity, all of which are relevant to the metabolic drivers of fatty liver. These findings are not liver-specific and come largely from observational research rather than controlled trials.

• Inflammation: Some research suggests that regular sauna use may be associated with lower systemic inflammatory markers such as C-reactive protein (CRP), though evidence in liver-specific populations is very limited.^[6]

• Stress reduction: Chronic psychological stress is associated with metabolic dysregulation; sauna use may support stress reduction, which could indirectly benefit metabolic health.

These are indirect, theoretical pathways rather than proven liver-specific effects. No sauna protocol has been shown in a randomised controlled trial to reduce liver fat content, improve liver enzymes, or slow fibrosis progression in people with MASLD.

People who should avoid sauna use or seek clinician advice before starting include those with decompensated cirrhosis, unstable cardiovascular disease, pregnancy, or severe frailty. Anyone considering sauna use as part of a broader wellness approach should discuss this with their GP, particularly if they have existing liver disease, cardiovascular conditions, or take regular medication.

What does the current evidence say about heat therapy and liver health?

Current evidence for heat therapy and liver health is preliminary, based mainly on observational studies and animal models. No UK guideline endorses sauna use as a liver-directed treatment.

The evidence base for heat therapy and liver health is emerging but remains preliminary, and no UK clinical guideline currently endorses sauna use as a liver-directed treatment. Most available research comes from observational studies, animal models, or small human trials, which limits the conclusions that can be drawn.

Several areas of research are worth noting:

• Finnish cohort studies, including work by Laukkanen and colleagues published in JAMA Internal Medicine and related journals, have associated regular sauna bathing with reduced all-cause cardiovascular mortality and lower rates of metabolic syndrome, conditions closely linked to MASLD. These are observational associations and do not establish causation; liver outcomes were not specifically examined.

• Animal studies have demonstrated that heat shock proteins (HSPs), produced in response to thermal stress, may have hepatoprotective effects, reducing oxidative stress and inflammation in liver tissue.^[9] Whether this translates meaningfully to humans with fatty liver disease is not yet established, and translational uncertainty is considerable.

• A small number of human studies have examined the effect of repeated sauna or hot water immersion on metabolic markers, including insulin sensitivity and lipid profiles, with some modest positive findings. However, sample sizes are small, follow-up periods are short, and liver-specific outcomes such as liver fat measured by MRI or liver enzyme normalisation are rarely reported.

In summary, while the biological rationale is not implausible, the current evidence does not support sauna use as an evidence-based intervention for fatty liver. Larger, well-designed trials examining liver-specific endpoints are needed before any firm clinical recommendation could be made. Patients should rely on NICE-aligned lifestyle interventions as their primary approach.

Are there any risks of using a sauna if you have liver disease?

People with liver disease face real risks from sauna use, including dehydration, hypotension, and medication interactions. Those with decompensated cirrhosis should seek specialist advice before using a sauna.

Sauna use carries specific risks for people with liver disease, and these should be carefully considered before starting or continuing regular sessions. The liver has important roles in metabolism and fluid and electrolyte homeostasis, which are relevant to heat exposure, though core body temperature regulation is primarily controlled by the hypothalamus and the skin's sweating response.

Key risks include:

• Dehydration: Sauna sessions cause significant fluid loss through sweating. In people with advanced liver disease, particularly those with cirrhosis, dehydration can precipitate or worsen complications such as hepatic encephalopathy or acute kidney injury.^[10][11]

• Hypotension: Heat causes peripheral vasodilation and a drop in blood pressure. People with cirrhosis already have altered haemodynamics and may be at greater risk of dizziness, falls, or syncope.

• Medicines and heat exposure: Some medicines commonly taken by people with liver disease may interact with the physiological effects of heat. Diuretics increase the risk of volume depletion and electrolyte disturbance during sauna use; beta-blockers may blunt the normal heart-rate response to heat. People taking any regular medicines should check with their GP or pharmacist before using a sauna, as individual circumstances vary.

• Alcohol-related liver disease: People who drink alcohol should be aware that combining alcohol with sauna use significantly increases the risk of dehydration, cardiovascular stress, and falls.

• Decompensated cirrhosis: People with decompensated cirrhosis (for example, those with ascites, a history of hepatic encephalopathy, variceal bleeding, or low sodium levels) should seek specialist advice before using a sauna and will generally be advised to avoid hot environments.

Practical safety tips for those who do use a sauna include staying well hydrated before and after sessions, keeping sessions short, and avoiding alcohol before or during sauna use.

Anyone with diagnosed liver disease should speak to their GP before using a sauna regularly. If you experience symptoms such as confusion, severe dizziness, yellowing of the skin or eyes (jaundice), or abdominal swelling after sauna use, contact your GP promptly. For sudden or severe symptoms, call 999 or go to your nearest A&E department.

Suspected adverse effects from any medicine or supplement taken alongside sauna use can be reported to the MHRA via the Yellow Card scheme at https://yellowcard.mhra.gov.uk/

What lifestyle changes does the NHS recommend for fatty liver?

NICE and the NHS recommend weight loss of 7 to 10 per cent, a Mediterranean-style diet, and at least 150 minutes of moderate aerobic activity weekly as the primary treatments for MASLD.

The NHS and NICE recommend a structured set of lifestyle changes as the primary and most effective approach to managing fatty liver disease, particularly MASLD. These interventions have the strongest evidence base and should form the foundation of any management plan.

Weight loss is the single most impactful intervention for MASLD. NICE NG49 and EASL clinical practice guidelines indicate that a sustained reduction in body weight of 7 to 10 per cent can significantly reduce liver fat content, improve liver enzyme levels, and in some cases reverse early fibrosis. Even a 3 to 5 per cent reduction can reduce liver fat meaningfully.

Dietary changes recommended include:

• Reducing intake of refined carbohydrates, added sugars, and ultra-processed foods

• Following a Mediterranean-style diet, which is rich in vegetables, legumes, whole grains, fish, and olive oil^[18][19]

• Limiting or avoiding alcohol: people with ALD are advised to abstain from alcohol entirely; people with MASLD, particularly those with fibrosis, should discuss alcohol intake with their clinician and many will be advised to avoid or strictly limit it, in line with UK Chief Medical Officers' low-risk drinking guidance

Physical activity plays an independent role beyond weight loss. Both aerobic exercise (such as brisk walking, cycling, or swimming) and resistance training have been shown to reduce liver fat. UK Chief Medical Officers' guidelines recommend at least 150 minutes of moderate-intensity aerobic activity per week for adults, alongside muscle-strengthening activities on two or more days per week.^[14][15]

Managing associated conditions such as type 2 diabetes, high blood pressure, and dyslipidaemia is also essential, as these conditions accelerate liver disease progression.

UK diagnostic and referral pathway: In primary care, FIB-4 or NFS scoring is used to stratify fibrosis risk. Where scores are indeterminate or high, or where there is clinical concern, ELF testing or referral to hepatology should be considered per NICE NG49. Red flags warranting prompt assessment include jaundice, ascites, confusion, or signs of decompensation.

For people seeking structured support with weight management as part of a broader health plan, Bolt Pharmacy is a GPhC-registered UK online pharmacy offering online weight-management consultations, with prescriber review and pharmacist support. Weight-management medicines are only prescribed where clinically appropriate following a consultation. Your GP remains the first point of contact for a formal MASLD diagnosis, monitoring, and referral to specialist hepatology services where needed.

Scientific References

1. A multisociety Delphi consensus statement on new fatty liver disease nomenclature.
2. Understanding the evolving nomenclature of steatotic liver disease.
3. Metabolic dysfunction-associated steatotic liver disease (NG49).
4. NG49 Recommendations for research.
5. Comparison of Referral Rates and Costs Using Fibrosis-4 and ELF Testing.
6. Longitudinal associations of sauna bathing with inflammation.
7. Association Between Sauna Bathing and Fatal Cardiovascular and All-Cause Mortality Events.
8. Association between sauna bathing and fatal cardiovascular and all-cause mortality events.
9. Hsp72 protects against liver injury via attenuation of hepatocellular death, oxidative stress, and JNK signaling. Journal of Hepatology.
10. A New Look at Precipitants of Overt Hepatic Encephalopathy in Cirrhosis. Digestive Diseases and Sciences.
11. Acute renal failure associated with liver disease in India: etiology and outcome. Renal Failure.
12. Non-alcoholic fatty liver disease (NAFLD).
13. Beta blockers.
14. Physical activity guidelines: UK Chief Medical Officers' report.
15. UK Chief Medical Officers' physical activity guidelines.
16. Physical activity guidelines for adults aged 19 to 64.
17. Exercise and non-alcoholic fatty liver disease: a systematic review and meta-analysis. Journal of Hepatology.
18. Metabolic Dysfunction-Associated Steatotic Liver Disease – consultation comments and responses (GID-NG10434).
19. Impact of weight loss and reduction of ultra-processed foods on liver fat content in MASLD: A randomized controlled trial. JHEP Reports.
20. A culturally adapted online Mediterranean diet intervention for MASLD (TIMA): study protocol for a randomized controlled trial. Trials.
21. Very low energy ketogenic diet vs. Mediterranean diet for MASLD: Superior steatosis reduction in a randomised pilot study. JHEP Reports.

Frequently Asked Questions