Liver Function Test (LFT): Understanding Your Report

By Dashvanth Healthcare Medical Team · Reviewed by our specialists · East Delhi

What Is a Liver Function Test (LFT)?

An LFT (also called LFTs or Liver Panel) is a blood test measuring several markers of liver health. It is used to detect liver disease, monitor liver conditions, and assess drug toxicity.

Key Components Explained

ALT (Alanine Aminotransferase) — Most Liver-Specific

• Normal: 7–56 U/L (males often higher)
• Elevated: liver cell damage — hepatitis, fatty liver (NAFLD), medications, alcohol
• Markedly elevated (>10× normal): acute hepatitis, ischaemic hepatitis, drug toxicity

AST (Aspartate Aminotransferase)

• Normal: 10–40 U/L
• Less liver-specific (also in muscle, heart, kidney)
• AST:ALT ratio >2 suggests alcoholic liver disease; >3 is strongly suggestive

ALP (Alkaline Phosphatase)

• Normal: 44–147 U/L
• Elevated: bile duct obstruction (gallstones, cholangitis), bone disease, pregnancy

GGT (Gamma-glutamyl Transferase)

• Normal: Men <73 U/L; Women <43 U/L
• Sensitive marker for alcohol use and liver disease; elevated in NAFLD

Bilirubin (Total)

• Normal: 0.2–1.2 mg/dL
• Jaundice visible at >2.5–3.0 mg/dL
• Elevated: haemolysis, hepatitis, bile duct obstruction, Gilbert syndrome (benign)

Albumin

• Normal: 3.5–5.0 g/dL
• Low: indicates chronic liver disease, malnutrition, or nephrotic syndrome
• Marker of synthetic function — a low albumin signals significant liver dysfunction

Prothrombin Time (PT) / INR

• Liver makes clotting factors; prolonged PT = severe liver disease