A “liver screen” is a group of blood tests used to investigate:

👉 unexplained abnormal LFTs

It helps identify:

viral hepatitis
autoimmune disease
metabolic causes
iron overload
chronic liver disease

In simple terms:

It looks for the common, treatable causes of liver injury.

This guide explains what each test is for and how to interpret it practically.

✅ First principle

Don’t order a liver screen blindly.

Always ask:

What pattern of LFTs am I trying to explain?

Because:

Hepatocellular → blood tests most useful
Cholestatic → imaging often more useful

A liver screen complements the clinical picture — it doesn’t replace thinking.

✅ What is usually included in a “liver screen”?

Most NHS liver screens include:

Core groups:

Viral hepatitis tests
Autoimmune markers
Iron studies
Metabolic tests
± Coeliac screen

Let’s break these down.

🟡 1. Viral hepatitis screen

Tests:

Hep B (HBsAg)
Hep C antibody (± PCR)

Why?

Common, treatable causes of chronic hepatitis

When positive:

👉 refer hepatology
👉 needs treatment/follow-up

When to suspect:

ALT raised
risk factors (travel, tattoos, IVDU, sexual exposure)

Always check these in unexplained ALT rise.

🟡 2. Autoimmune screen

Tests:

ANA
ASMA (smooth muscle)
AMA
IgG/IgM levels

Why?

Detect autoimmune liver diseases

ANA / ASMA + high IgG

👉 Autoimmune hepatitis

Think:

young/middle-aged
high ALT
other autoimmune disease

Needs specialist treatment (steroids)

AMA + high ALP

👉 Primary biliary cholangitis (PBC)

Think:

middle-aged women
cholestatic pattern

Autoimmune causes are less common but important not to miss.

🟡 3. Iron studies

Tests:

Ferritin
Transferrin saturation

Why?

Detect haemochromatosis

Pattern:

High ferritin + high transferrin sat (>45–50%)
👉 iron overload

Needs:

genetic testing
referral

Remember:
Ferritin alone is not enough (often raised in inflammation).

🟡 4. Metabolic / fatty liver tests

Tests:

HbA1c
Lipids
BMI assessment

Why?

MASLD (fatty liver) is the most common cause of abnormal LFTs

Think:

obesity
diabetes
hypertension

Very common in real practice.

🟡 5. Coeliac screen

Test:

tTG-IgA

Why?

Coeliac disease can cause:

mild LFT rise
abnormal liver enzymes
iron deficiency

Often forgotten.

Easy test to add.

🟡 6. Other tests sometimes included

Depending on situation:

Alpha-1 antitrypsin
Ceruloplasmin (Wilson’s disease in young)
Thyroid function
Immunoglobulins

Used selectively.

Not everyone needs these.

✅ Step-by-step practical approach

When you see unexplained abnormal LFTs:

Step 1 – Look at pattern

ALT vs ALP vs INR

Step 2 – Basic history

Alcohol, drugs, metabolic risk

Step 3 – Liver screen bloods

Viral + autoimmune + iron + coeliac

Step 4 – Imaging if cholestatic

Ultrasound/MRCP

Most diagnoses come from these steps.

✅ Practical examples

Scenario 1

ALT 250, viral hepatitis positive
→ chronic hepatitis

Scenario 2

ALP 400, AMA positive
→ PBC

Scenario 3

Ferritin 900, transferrin sat 65%
→ haemochromatosis

Scenario 4

Normal screen, overweight diabetic
→ MASLD likely

Scenario 5

ANA/ASMA positive, IgG high
→ autoimmune hepatitis

❌ Common junior mistakes

Ordering liver screen for obvious fatty liver
Forgetting transferrin saturation
Not imaging cholestatic pattern
Ignoring medications/alcohol
Sending rare tests unnecessarily

Remember:
History + pattern often gives the answer before bloods.

✅ When to refer

Refer if:

positive viral markers
positive autoimmune markers
iron overload
persistent abnormal LFTs
suspected chronic liver disease
unclear diagnosis

Don’t refer simple MASLD without red flags.

✅ Simple rule to remember

Think:

Viral
Autoimmune
Iron
Metabolic

These four explain most liver problems.

That’s what your liver screen is looking for.

✅ Take-home concept

A liver screen looks for the common, treatable causes of liver injury.
Use it to confirm your suspicion — not as a fishing expedition.