NAFLD / MASLD .

Metabolic fatty liver disease is now the most common cause of chronic liver disease in the UK.
Most patients are asymptomatic, but a small proportion progress to cirrhosis, liver failure, and hepatocellular carcinoma.

This guide focuses on how to recognise it, assess risk, and manage patients safely in real NHS practice.

What is NAFLD / MASLD?

NAFLD (Non-Alcoholic Fatty Liver Disease)
Old term for fatty liver not caused by alcohol.

MASLD (Metabolic dysfunction–Associated Steatotic Liver Disease)
Newer term, now increasingly used.

In simple terms:

Fat accumulation in the liver driven by metabolic disease.

Spectrum:

  • Simple steatosis (fat only)
  • Steatohepatitis (inflammation – NASH/MASH)
  • Fibrosis
  • Cirrhosis

Not all fatty liver is harmless.

How does it present?

Most patients:

  • No symptoms
  • Incidental abnormal LFTs
  • Fatty liver found on ultrasound

Sometimes:

  • Fatigue
  • Right upper quadrant discomfort

Advanced disease may present with:

  • Cirrhosis
  • Ascites
  • Encephalopathy
  • Variceal bleeding

Often diagnosed very late.

Common risk factors (think practically)

Classic metabolic profile:

  • Obesity
  • Type 2 diabetes
  • Hypertension
  • Dyslipidaemia
  • Metabolic syndrome

If you see:

Overweight + diabetic + abnormal ALT
Think MASLD until proven otherwise.

On the ward or clinic, always ask

Is this just fatty liver — or could this patient already have fibrosis?

Because:

  • Steatosis alone → low risk
  • Fibrosis/cirrhosis → high risk

Your job is risk stratification, not just diagnosis.

Typical blood test pattern

Often mild abnormalities:

  • Mild ALT elevation
  • ALT > AST (early disease)
  • Normal bilirubin
  • Normal INR

But:
Normal LFTs do not exclude significant fibrosis.

This is a common trap.

Initial assessment (what juniors should actually do)

If you see suspected fatty liver:

Do early:

  • Alcohol history (exclude alcohol-related disease)
  • Check BMI
  • Check diabetes status
  • Lipid profile
  • HbA1c
  • Basic liver screen (viral, autoimmune if unclear)
  • Ultrasound liver

Then:

  • Calculate FIB-4 score (very useful and easy)

Risk stratification (practical NHS approach)

Step 1 – FIB-4:

Uses age, AST, ALT, platelets

  • Low → low risk → manage in primary care
  • Indeterminate/high → refer for FibroScan/hepatology

Step 2 – FibroScan (if available):

  • Assesses fibrosis non-invasively

Most patients don’t need biopsy.

Management on the ward or clinic

There is no magic drug.

Main treatment:

Lifestyle and metabolic control

Practical steps:

  • Weight loss (target 7–10%)
  • Diabetes optimisation
  • Lipid control
  • BP control
  • Exercise
  • Alcohol reduction
  • Avoid hepatotoxic drugs

Small changes can significantly reduce progression.

When to refer to hepatology

Refer if:

  • FIB-4 high
  • FibroScan shows fibrosis
  • Signs of cirrhosis
  • Unexplained LFTs
  • Diagnostic uncertainty

Do not refer every patient with mild ALT elevation.

Common mistakes juniors make

  • Ignoring fatty liver as “benign”
  • Not checking metabolic risk factors
  • Over-investigating low-risk patients
  • Missing fibrosis
  • Not counselling about lifestyle
  • Forgetting cardiovascular risk (often higher than liver risk)

Remember:
Most MASLD patients die from heart disease, not liver failure.

Take-home concept

Fatty liver is common, but fibrosis is dangerous.
Your role is to identify high-risk patients early and focus on metabolic optimisation, not just LFT numbers.