Liver Function Tests - A Patients Guide

Dr. Karuturi Subrahmanyam
Apr 24
2 min read

Updated: Apr 28

A Liver Function Test (LFT) is a group of blood tests that check how well your liver is working. It helps detect liver damage, inflammation, infection, or diseases like hepatitis, fatty liver, or cirrhosis. Your doctor may order this test if you have symptoms such as jaundice (yellowing of eyes/skin), fatigue, dark urine, or abdominal pain.

Why is the Liver Important?

The liver is a vital organ that:

Filters toxins from the blood
Helps digest food (by producing bile)
Stores energy and nutrients
Regulates blood clotting
Processes medications and hormones

What Does a Liver Function Test Measure?

LFTs include several blood markers:

ALT (Alanine Aminotransferase) – High levels may indicate liver cell injury.
AST (Aspartate Aminotransferase) – Also signals liver damage, though it can rise in heart/muscle issues too.
ALP (Alkaline Phosphatase) – Elevated in bile duct blockage or liver disease.
GGT (Gamma-glutamyl transferase) – Sensitive to alcohol use or bile problems.
Bilirubin – A pigment made when red blood cells break down. High levels cause jaundice.
Albumin – A protein made by the liver; low levels may suggest chronic liver disease.
Total protein – Measures all proteins in the blood, including albumin and globulins.

How to Prepare for the Test

Fasting: Some doctors may recommend 8–12 hours of fasting.
Medication: Inform your doctor about any medications, alcohol use, or herbal supplements.
No alcohol: Avoid alcohol for at least 24 hours before the test.

What Do Abnormal Results Mean?

High ALT/AST: May indicate hepatitis, fatty liver, or liver inflammation.
High ALP/GGT: May suggest bile duct problems, gallstones, or alcohol-related liver disease.
High bilirubin: Indicates issues with bile flow or red blood cell breakdown.
Low albumin or total protein: May point to chronic liver disease or malnutrition.

Note: Results should be interpreted by your doctor, considering your symptoms and other test findings.

When is the Test Advised?

You may need an LFT if you:

Have symptoms of liver disease
Use alcohol or medications that affect the liver
Have hepatitis B or C
Have metabolic or autoimmune conditions
Are being monitored for known liver disease

Summary

Liver Function Tests are essential tools to detect and monitor liver health. While abnormal results can be concerning, many liver problems are manageable if caught early. Always consult your doctor to understand what your results mean and what steps to take next.

Dr. Karuturi Subrahmanyam, MD, FRCP (London), FACP (USA)

Internal Medicine Specialist

Kify Hospital

Danavaipeta

Rajahmundry

Phone : 85000 23456