Liver Function Test (LFT)

Liver Function Test Meaning

The liver function test or LFT blood test means a test that is done to assess the functioning of the liver and measure the different enzymes, proteins, and other substances made by the liver.  

The liver plays a crucial role in the detoxification of several metabolites and the production of proteins and digestive enzymes. The liver also plays a prominent role in the regulation of red blood cells (RBCs), and glucose storage and production.  

Elevation of parameters as seen in liver profile tests assists the doctor in identifying the area of hepatic damage and the elevation patterns direct them around the possible causes of the damage.

Reason/when to take the LFT Test

The reason for liver function testing or undergoing liver profile tests is usually the presence of symptoms of liver disease. These include: 

• Dark or light-coloured stools 

• Fatigue 

• Yellowing of sclera, skin and nail bed 

• Pain in the stomach region 

• Abdominal pain 

• Diarrhoea 

• Nausea that may or may not be accompanied by vomiting 

• Jaundice 

• Dark-coloured urine 

Further, you may also need the tests if you have the following risk factors: 

• You have a family history of liver disease 

• You are exposed to the hepatitis virus 

• You have an alcohol use disorder 

• You are taking any medicine that can affect the functioning of the liver.2 

If you have the above-mentioned symptoms or risk factors, your doctor would advise LFT tests to diagnose hepatitis or other liver problems.  

If you have already been diagnosed with liver disease, the doctor might want to evaluate the effect of the treatment given and monitor your progress using these tests.  

Additionally, your doctor might recommend a liver test to assess the extent of scarring of the liver and track the potential side effects of certain medicines.

LFT Parameters

The common LFT blood test parameters are:  

• Liver enzymes test: The predominant liver enzymes are aspartate aminotransferase (AST), alanine transaminase (ALT), gamma-glutamyl transferase (GGT), and alkaline phosphatase (ALP); liver injury is indicated by an increase in their values. 

• Total protein test:  A total protein test checks the level of proteins in your blood. The liver produces different kinds of proteins, and low protein levels may indicate a malfunctioning. 

• Bilirubin Test: Bilirubin is a waste material produced by the liver and an imbalance in the bilirubin indicates that the liver is not functioning properly and may fall outside the liver function test normal range.

• Prothrombin Time test (PTT): This test estimates the duration of clot formation in the given sample. Since the proteins needed for blood clotting are produced by the liver, this test is an indicator of liver function.   

• Lactate Dehydrogenase (LDH): LDH is an enzyme present in several body cells including the liver and is released into the blood during injury/damage.

Understanding the Liver Function Test (LFT) report

Your LFT results are compared with the normal values, which typically helps a doctor figure out the cause for the abnormal levels. If you have an LFT normal report, it means your liver is healthy.  

• The normal values of the LFT are:  

• Aspartate transaminase: 5 to 30 IU/L 

• Gamma-glutamyl transferase: 6-50 IU/L 

• Albumin: 35-50 g/L 

• Total protein: 60-80 g/L 

• Bilirubin: 2-17 µmol/L 

• Alanine transaminase: 4-36 IU/L 

• Alkaline phosphatase: 30-120 IU/L 

• Direct bilirubin: 0-6 µmol/L 

• Lactate dehydrogenase: 50-150 IU/L 

• Altered levels are indicative of liver disease. 

Hepatocellular disease (damage or cancer of liver cells) is indicated by increases in ALT and AST that are not proportional to increases in ALP and bilirubin.  

A cholestatic pattern (obstruction of bile flow or decreased secretion by liver cells) is characterised by an increase in ALP and bilirubin that is out of proportion to ALT and AST.  

The ability of the liver to create albumin and vitamin K-dependent clotting factors is used to grade the liver's actual performance.

Conditions/disease detected under Liver Function Test

The liver tests show clear abnormalities in many conditions. These include:  

• Alcohol-related damage 

• Diabetes 

• Liver cancer 

• Hepatitis A, B, and C 

Further, a few diseases that may alter liver function are: 

• Autoimmune hepatitis 

• Viral hepatitis 

• Hemochromatosis 

• Hepatic steatosis and non-alcoholic steatohepatitis 

• Celiac disease 

• Wilson’s disease 

• Alpha-1 antitrypsin deficiency

Preparations for LFT Test

You need to fast (avoid both liquids and solids) for 10-12 hours before the liver function test or liver profile test or cholesterol test. This fasting is vital for accurate liver function test results, as deviations from the liver function test normal value can signal different health conditions. For the test, a blood sample will be taken by a phlebotomist and sent for examination. The pathologist will search for particularly high or low concentrations of various chemicals or substances in the blood as mentioned above.

Risks and Limitations of Liver Function Blood Test

There is no risk when you undergo LFT. A small needle is inserted to collect the blood sample, which might feel like a minor sting or discomfort. Following the procedure, the area where the needle was inserted could feel sore. Other risks encompass the possibilities of bleeding, infection, bruising, and experiencing dizziness. However, these symptoms are transient and resolve spontaneously.

Booking LFT Test at Home with Orange Health Labs across Cities 

Orange Health Labs provides the fastest and most accurate liver function test results at your doorstep. Offering several packages to choose from, along with the facility of at-home blood testing. 

Orange Health Labs is your best option to get all your blood tests done. You can now make an appointment by just following the steps mentioned below: 

• Log into ‘www.orangehealth.in’  

• Submit your details. 

• Within 60 minutes, our trained person will be at your doorstep for sample collection.