Managing Abnormal LFTs

Abnormal liver function tests (LFTs) are one of the most common reasons for referrals to medical and gastro teams in the NHS.

Most abnormalities are mild and incidental.
A small number represent serious liver disease that needs urgent action.

The challenge is knowing:

Who is safe to monitor
and who needs escalation

This guide focuses on a simple, safe, practical approach you can use on the ward or in clinic.

✅ First principle

Don’t react to numbers.

Always ask:

Is this patient clinically sick, or just biochemically abnormal?

Because:

  • Sick + abnormal LFTs → urgent
  • Well + mild abnormalities → usually routine workup

Clinical status comes first.

✅ Step 1 – Assess the patient, not the blood test

Before interpreting results, check:

  • Observations / NEWS
  • Mental state
  • Jaundice
  • Abdominal pain
  • Fever
  • Confusion
  • Haemodynamic stability

🚨 Red flags:

  • Encephalopathy
  • INR rising
  • Hypotension
  • Sepsis
  • Severe pain
  • Marked jaundice

If present → escalate early (possible liver failure/cholangitis/sepsis)

Do not sit on these patients.

✅ Step 2 – Identify the LFT pattern

Now look at the labs.

Don’t read each value individually — classify the pattern.

Hepatocellular (ALT/AST predominant)

ALT >> ALP

Think:

  • MASLD
  • Alcohol
  • Viral hepatitis
  • Drugs
  • Autoimmune
  • Ischaemia

👉 Mostly blood-test workup

Cholestatic (ALP predominant)

ALP >> ALT

Think:

  • Gallstones
  • Cholangitis
  • Obstruction
  • PSC/PBC
  • Malignancy

👉 Needs imaging first (ultrasound)

Synthetic failure

Low albumin / high INR

Think:

  • Cirrhosis
  • Acute liver failure
  • Severe hepatitis

👉 High risk → escalate

Pattern tells you the next step.

✅ Step 3 – Review the history properly (high yield)

Most diagnoses come from history, not tests.

Ask:

Alcohol

  • How much exactly?
  • For how many years?

Medications

  • Antibiotics
  • Statins
  • Herbal supplements
  • Paracetamol
  • New drugs recently?

Metabolic risk

  • Obesity
  • Diabetes
  • Hypertension

Risk factors

  • Travel
  • IV drug use
  • Tattoos
  • Sexual exposure
  • Family history

Often the answer is already here.

✅ Step 4 – Order focused investigations (not everything)

Don’t shotgun tests. Be targeted.

If hepatocellular pattern:

Order:

  • Viral hepatitis screen (B/C)
  • Liver autoimmune screen (ANA/ASMA/IgG)
  • Ferritin/iron studies
  • HbA1c/lipids (metabolic)
  • Ultrasound liver

If cholestatic pattern:

Order:

  • Ultrasound liver first

Then:

  • MRCP if obstruction unclear
  • AMA (for PBC)

Imaging is more important than bloods here.

If synthetic dysfunction:

  • Urgent senior review
  • Consider admission if outpatient
  • Full liver screen
  • Early gastro/hepatology involvement

These patients are not routine.

✅ Step 5 – Decide urgency (this is key)

This is what juniors struggle with most.

🚨 Urgent referral / admission

  • Encephalopathy
  • INR rising
  • Bilirubin rapidly rising
  • Sepsis + jaundice
  • Suspected cholangitis
  • Acute hepatitis with systemic illness
  • Known cirrhosis deteriorating

⚠️ Early outpatient referral

  • Persistent abnormal LFTs (>3–6 months)
  • Unclear cause
  • Suspected autoimmune/viral disease
  • Fibrosis suspected

✅ Manage in primary care / locally

  • Mild MASLD
  • Known alcohol-related pattern
  • Small stable ALT rise
  • Clear benign explanation

Not every ALT 60 needs gastro.

✅ Common real-life scenarios

Scenario 1

ALT 85, overweight, diabetic
→ MASLD likely
→ lifestyle advice + routine follow-up

Scenario 2

ALP 500, jaundice, fever
→ cholangitis
→ antibiotics + urgent referral

Scenario 3

ALT 900 after co-amoxiclav
→ drug-induced
→ stop drug + monitor

Scenario 4

Albumin 22, INR 2.0, ascites
→ decompensated cirrhosis
→ escalate early

❌ Common mistakes juniors make

  • Over-investigating mild abnormalities
  • Ignoring synthetic dysfunction
  • Missing cholestasis and not imaging
  • Forgetting medication history
  • Referring without basic workup
  • Treating numbers instead of the patient

✅ Simple ward algorithm

When you see abnormal LFTs:

  1. Is the patient sick?
  2. What’s the pattern?
  3. Does history explain it?
  4. Bloods or imaging?
  5. Urgent vs routine referral?

That’s your whole decision tree.

✅ Take-home concept

Most abnormal LFTs are benign.
A few are dangerous.
Spot the dangerous ones early, investigate logically, and avoid unnecessary referrals.