Lab Tests for Liver Disease
The liver performs over 500 functions. When it's damaged — by alcohol, fatty infiltration, viral hepatitis, or medications — specific enzyme patterns emerge. Understanding which enzymes are elevated, and in what ratio, tells your doctor where to look next.
Clinical overview
Liver function tests divide into two groups: hepatocellular markers (ALT, AST — elevated when liver cells are dying) and cholestatic markers (ALP, GGT — elevated when bile ducts are blocked or inflamed). The pattern and ratio between them narrow the diagnosis.
Primary tests ordered for Liver Disease
These are the tests most commonly ordered first when liver disease is suspected or being monitored.
Liver Function Tests (LFTs)
Your LFTs came back abnormal and you've been left with a page of numbers and no explanation. ALT,…
Comprehensive Metabolic Panel (CMP)
Your comprehensive metabolic panel came back with a few flags and you're not sure which ones to focus…
Iron Studies (Ferritin, Iron & TIBC)
A low haemoglobin can have many causes. Iron studies — ferritin, serum iron, TIBC, and transferrin saturation —…
What to expect
- 🍺 Alcohol history is critical — alcohol is the most common cause of isolated GGT elevation.
- 💊 Medication review is essential — many common drugs cause elevated LFTs.
- ⏰ No fasting is required for LFTs, though a fatty meal can transiently elevate ALP.
- 📊 Pattern interpretation: hepatocellular vs cholestatic drives the investigation.
- 🔄 A single mildly elevated result should be repeated before further investigation.
Testing frequency
Also commonly ordered
These tests are frequently added to the primary panel based on initial results or specific clinical circumstances.
Hepatitis B (HBsAg)
Surface antigen — the primary screen for chronic hepatitis B infection.
Hepatitis C (anti-HCV)
Antibody screen for hepatitis C — the most common cause of chronic liver disease in many populations.
PT / INR
Prothrombin time — the liver makes clotting factors. Prolonged PT indicates impaired synthetic function.
Albumin
Made exclusively by the liver. Chronic low albumin indicates loss of synthetic function in advanced disease.
Alpha-fetoprotein (AFP)
Tumour marker for hepatocellular carcinoma. Measured every 6 months in cirrhosis surveillance.
ANA / Anti-SMA
Autoimmune hepatitis antibodies — particularly in young women with elevated ALT and no other cause.
Urgent result thresholds
These result patterns require prompt clinical attention — always discuss with your doctor rather than interpreting alone.
Acute hepatitis (viral, drug, ischaemic). Hepatology referral within 24–48 hours.
Visible jaundice — biliary obstruction or hepatocellular failure must be excluded urgently.
Impaired synthetic function — consider acute liver failure if new-onset with jaundice.
Rising AFP in cirrhosis — hepatocellular carcinoma must be excluded with urgent imaging.
Medical Disclaimer: This guide is for educational reference only. It does not constitute medical advice and should not replace consultation with a qualified healthcare professional. Always discuss your test results with your doctor. Full disclaimer →