Can COVID Cause Fatty Liver? Risks and NHS Care

Can COVID cause fatty liver? Evidence gathered since the pandemic began suggests that SARS-CoV-2 infection can contribute to the development or worsening of hepatic steatosis, particularly in those who experience moderate to severe illness. The relationship involves a combination of systemic inflammation, metabolic disruption and hypoxia rather than a single clear mechanism. This article explains how coronavirus affects the liver, who faces the greatest risk, what symptoms to watch for, and how COVID-related fatty liver is diagnosed and managed within the NHS.

Can COVID-19 actually cause fatty liver disease?

COVID-19 can contribute to new or worsened hepatic steatosis through inflammatory, metabolic and possible direct viral mechanisms, though mild liver enzyme changes during acute infection are often transient and resolve without intervention.

COVID-19 can contribute to the development or worsening of fatty liver disease, though the relationship is complex and the evidence base continues to evolve. Fatty liver disease, known medically as hepatic steatosis, involves an abnormal accumulation of fat within liver cells. Studies published since the pandemic began have found associations between SARS-CoV-2 infection and elevated liver enzymes and, in some cases, new or worsened hepatic steatosis, particularly in people who experience moderate to severe illness. These findings reflect associations rather than confirmed causation in all patients.

It is important to note that mild liver enzyme abnormalities are common during acute COVID-19 and are often transient, resolving as the infection clears. Persistent abnormalities beyond the acute phase warrant GP review. COVID-19 appears to trigger a combination of inflammatory, metabolic and, potentially, direct viral processes that together may promote fat accumulation in the liver. Some studies have observed that people with no prior liver disease developed signs of hepatic steatosis following COVID-19 infection, while others with pre-existing fatty liver disease experienced a deterioration in their condition.

A note on terminology: fatty liver disease has historically been called non-alcoholic fatty liver disease (NAFLD), and its more advanced inflammatory form non-alcoholic steatohepatitis (NASH). UK and European bodies are increasingly adopting the updated terms metabolic dysfunction-associated steatotic liver disease (MASLD) and metabolic dysfunction-associated steatohepatitis (MASH) alongside NAFLD and NASH. NICE guidance currently uses NAFLD and NASH, so both sets of terms may be encountered.^[3][13]

The evidence base continues to evolve, and UK bodies including NICE and NHS England are monitoring emerging research. COVID-related liver changes are a recognised area of concern following infection, particularly in those with severe disease or prolonged symptoms consistent with long COVID (as described in NICE NG188). If you are concerned about your liver health following a COVID-19 infection, speaking to your GP is the appropriate first step.

How does coronavirus affect the liver?

SARS-CoV-2 affects the liver primarily through systemic inflammation, metabolic disruption and hypoxia, with direct viral injury via ACE2 receptors on bile duct cells considered a lesser but possible contributor.

SARS-CoV-2 affects the liver through several overlapping mechanisms, including systemic inflammation, metabolic disruption, hypoxia and, possibly, some degree of direct viral injury. The virus binds to the ACE2 receptor, which is expressed on bile duct cells (cholangiocytes) and, to a lesser extent, on liver cells (hepatocytes). Whether direct hepatocyte infection is a major driver of liver injury remains debated among hepatologists; immune-mediated and metabolic mechanisms are generally considered more significant.

The systemic inflammatory response triggered by COVID-19 plays a well-recognised role. The surge of inflammatory proteins during severe infection, sometimes called a cytokine storm, can cause widespread organ stress including hepatic inflammation. Elevated inflammatory markers such as C-reactive protein and interleukin-6 have been associated with liver enzyme abnormalities in hospitalised patients. Well-established patterns of liver injury in COVID-19 include transaminitis (raised ALT and AST), cholestatic changes and, in severe illness, ischaemic hepatitis related to hypoxia.

Metabolic disruption is another important pathway. COVID-19 illness often leads to reduced physical activity, altered eating patterns and prolonged bed rest, all of which can promote insulin resistance and fat accumulation in the liver. These effects are particularly relevant in people who already have metabolic risk factors.

Some medications used during COVID-19 illness can also affect the liver. Corticosteroids such as dexamethasone may cause transient liver enzyme changes and, with prolonged use, can contribute to metabolic effects; short courses at standard doses are generally well tolerated but patients with liver concerns should discuss this with their prescriber.^[6] Certain antivirals used in COVID-19 treatment have also been associated with transient liver enzyme elevations in some patients; specific effects vary by drug and your prescriber or pharmacist can advise. If you are taking any medicine and are concerned about its effects on your liver, you can also report suspected side effects to the MHRA via the Yellow Card scheme at yellowcard.mhra.gov.uk.

Finally, hypoxia during severe respiratory illness can impair liver function, as the liver is highly sensitive to oxygen supply. Together, these mechanisms explain why liver involvement is relatively common in moderate to severe COVID-19, even in people without pre-existing liver conditions.

Who is most at risk of liver problems after COVID?

People with obesity, type 2 diabetes, hypertension or pre-existing fatty liver disease are most at risk, as are those who experienced severe COVID-19 requiring hospitalisation or prolonged oxygen therapy.

People with pre-existing metabolic conditions are most at risk of developing or worsening liver problems following COVID-19 infection. Specifically, those with obesity, type 2 diabetes, hypertension or pre-existing fatty liver disease (NAFLD or MASLD) appear to be disproportionately affected. These conditions are already associated with hepatic steatosis and insulin resistance, and COVID-19 infection can act as an additional stressor. It is worth noting that abnormal liver tests can occur in people without obvious metabolic risk factors, so a high index of suspicion is appropriate in anyone with persistent symptoms after COVID-19.

Severity of COVID-19 illness is also a key risk factor. Patients who required hospitalisation, intensive care or prolonged oxygen therapy are more likely to show significant liver enzyme abnormalities and structural liver changes compared with those who had mild illness managed at home. Long COVID, characterised by persistent symptoms lasting beyond 12 weeks from initial infection (as defined in NICE NG188), has been associated with ongoing liver enzyme abnormalities in some patients, though the evidence on biopsy-proven liver inflammation in this group remains limited.^[1][2]

Older adults and men appear to face a somewhat higher risk of liver complications, consistent with broader patterns seen in COVID-19 outcomes, though data specific to hepatic outcomes in the UK population are still emerging. People who consume alcohol regularly or who have other liver conditions, such as autoimmune hepatitis or viral hepatitis, may also be more vulnerable to compounding liver injury.

Regarding medications taken during COVID-19 illness: paracetamol is safe at the recommended adult dose (up to 1 g per dose, up to four times daily, with at least four hours between doses, and no more than 4 g in 24 hours).^[7][8] It is important not to exceed this dose and to check that other products you are taking do not also contain paracetamol. People with liver disease or low body weight should seek pharmacist or GP advice before use. If you fall into any of these higher-risk groups and have had COVID-19, discussing liver health monitoring with your GP is advisable.

What symptoms should I look out for with fatty liver?

Fatty liver is often asymptomatic, but persistent fatigue, upper right abdominal discomfort or nausea after COVID-19 warrant GP review; jaundice, dark urine or abdominal swelling require prompt medical assessment.

Fatty liver disease is frequently asymptomatic in its early stages, meaning many people have no obvious warning signs until the condition has progressed. However, some individuals do experience symptoms that may indicate hepatic steatosis or more advanced liver disease following COVID-19 infection.

Commonly recognised symptoms that may suggest fatty liver disease include:

• Persistent fatigue or low energy, which can overlap with long COVID symptoms and make identification more challenging

• A dull ache or discomfort in the upper right abdomen, where the liver is located

• Nausea or a general feeling of being unwell

It is worth noting that abdominal weight gain and difficulty concentrating (brain fog) are features associated with metabolic syndrome and long COVID rather than being characteristic symptoms of fatty liver disease itself. They are mentioned here only to acknowledge that these experiences are common in people who may also have liver involvement, and should prompt a broader conversation with your GP rather than being attributed to liver disease alone.

If fatty liver disease progresses to a more advanced stage, such as metabolic dysfunction-associated steatohepatitis (MASH, previously called NASH) or cirrhosis, more serious symptoms may develop. These can include jaundice (yellowing of the skin or whites of the eyes), dark urine, pale stools, significant abdominal swelling (ascites), easy bruising or confusion. These symptoms require prompt medical assessment, and you should contact your GP without delay if they occur. If you develop sudden, severe abdominal pain alongside jaundice or confusion, or if you vomit blood or notice black, tarry stools, seek urgent assessment via NHS 111 or attend A&E if the situation appears life-threatening.

Because fatty liver is often silent, routine blood tests and imaging are the most reliable way to detect it, particularly in those who have had significant COVID-19 illness or who have metabolic risk factors.

How is COVID-related fatty liver diagnosed and managed on the NHS?

Diagnosis follows NICE NG49, using liver function tests, FIB-4 fibrosis scoring, ultrasound and FibroScan; management focuses on lifestyle modification, metabolic risk factor control and regular monitoring.

COVID-related fatty liver is typically diagnosed through a combination of blood tests, imaging and clinical assessment, following pathways broadly consistent with NICE guidance on non-alcoholic fatty liver disease (NICE NG49). Your GP will usually begin with liver function tests (LFTs), which measure enzymes such as alanine aminotransferase (ALT) and aspartate aminotransferase (AST). It is important to note that ALT and AST can be within the normal range even when steatosis is present, so people with metabolic risk factors may warrant further assessment even if initial blood tests appear normal. A full blood count, fasting glucose and lipid profile are also commonly requested to assess metabolic risk factors, and other causes of abnormal liver tests (including alcohol use, viral hepatitis, autoimmune liver disease and medication effects) will typically be considered and excluded.

NICE NG49 recommends that GPs use a validated fibrosis risk score as a first-line tool to identify people at higher risk of significant liver fibrosis.^[3][4] The FIB-4 score and the NAFLD fibrosis score are the most widely used; these combine routine blood test results and clinical information to estimate fibrosis risk. Where the score indicates intermediate or higher risk, the enhanced liver fibrosis (ELF) test may be used to assess advanced fibrosis more precisely. Referral thresholds and local pathways vary between Integrated Care Boards (ICBs), so your GP will advise on what is available in your area.

If blood tests and risk scoring suggest liver involvement, your GP may refer you for an ultrasound scan of the abdomen, which can detect increased echogenicity consistent with hepatic steatosis. Ultrasound can identify steatosis but does not reliably stage fibrosis.^[19] FibroScan (transient elastography) may be arranged in secondary care to assess liver stiffness.^[9][10] Liver biopsy is reserved for cases where the diagnosis remains uncertain or where more advanced disease is suspected.

Management of COVID-related fatty liver on the NHS focuses primarily on addressing underlying risk factors. NICE NG49 recommends lifestyle modification as the cornerstone of management, including:

• Gradual, sustained weight loss through a balanced diet and increased physical activity

• Optimising control of type 2 diabetes, hypertension and raised cholesterol

• Reducing or eliminating alcohol consumption

• Regular monitoring of liver function and metabolic markers

There is currently no licensed medication specifically for NAFLD or MASLD in the UK, though research into pharmacological treatments is ongoing.^[11][12] For those managing weight as part of their liver health plan, Bolt Pharmacy is a GPhC-registered UK online pharmacy offering online weight-management consultations, with prescriber review and pharmacist support, where clinically appropriate options may be considered following consultation. Follow-up with your GP or a hepatology specialist will depend on the severity of your condition and your response to lifestyle changes.

Scientific References

1. COVID-19 rapid guideline: managing the long-term effects of COVID-19 (NG188).
2. Long COVID.
3. Metabolic dysfunction-associated steatotic liver disease (MASLD): assessment and management (NG49).
4. Assessment for advanced liver fibrosis in people with MASLD (NG49 chapter).
5. Advice on physical activity, diet and alcohol – Liver disease (QS152).
6. COVID-19 treatment summaries – BNF.
7. Paracetamol – BNF.
8. Paracetamol for adults.
9. DIAGNOSTICS ASSESSMENT PROGRAMME – FibroScan (transient elastography).
10. FibroScan for assessing liver fibrosis and cirrhosis outside secondary care – final scope.
11. Draft scope post-referral – MASLD/MASH pharmacological treatment (GID-TA11477).
12. Resmetirom (Rezdiffra) authorised to treat metabolic dysfunction-associated steatohepatitis (MASH) in adults.
13. Scope for guideline update (starting 2025) – NAFLD/NASH terminology.
14. Non-alcoholic fatty liver disease (NAFLD).
15. A Human Pluripotent Stem Cell-based Platform to Study SARS-CoV-2 Tropism and Model Virus Infection in Human Cells and Organoids.
16. Economic evaluation of non-invasive test pathways for high-risk metabolic dysfunction-associated steatotic liver disease (MASLD) in the United Kingdom (UK).
17. Meta-analysis: Enhanced liver fibrosis test to identify hepatic fibrosis in chronic liver diseases.
18. Accuracy of non-invasive tests for diagnosing liver fibrosis and steatosis: A systematic review.

Frequently Asked Questions