Liver Function Test (LFT)

Liver is one of the essential organs in the body. It performs various functions, including detoxification, protein synthesis and the production of biochemicals vital for digestion. Thus, it makes the liver prone to many diseases. Hence, getting LFT done for general check-ups, investigating liver diseases or assessing liver functionality is vital.

There are a variety of liver function tests that assess proteins and enzymes in the blood. Any fluctuations in these LFT test values indicate liver abnormality.

Other names of liver function test

• Liver panel
• Liver function panel
• Liver profile hepatic function panel
• Hepatic function test
• Liver profile
• Liver function evaluation
• LFT

What does the liver function test detect/measure and for whom is this prescribed?

The liver function test usually measures the levels of the following enzymes: Alanine transaminase (SGPT/ALT), Aspartate transaminase (SGOT/AST), Alkaline phosphatase (ALT), Gamma-glutamyl transferase (GGT), Serum albumin, Prothrombin time (PT) and bilirubin. 

Your physician may request a liver function test if you are experiencing any of the symptoms mentioned below or any other symptoms of liver disorder.

• Abdominal pain
• Weight loss
• Nausea
• Diarrhoea
• Lack of energy or fatigue
• Jaundice
• Abnormal bleeding
• Vomiting
• Fluid retention
• Dark-coloured urine
• Light-coloured stools   

Some diseases for which a doctor can prescribe liver function tests are:

• Jaundice
• Hepatitis
• Cirrhosis
• Fatty liver
• Chronic alcoholic liver disease 

Following the diagnosis, the treatment for liver disease is initiated by the hepatologist or M.D. physician.

The LFT test may assist your treating physician in determining how your treatment is ongoing and regulate the medications if necessary or modify them.

The liver function test applies to males and females, both adults and children. If you are on blood thinners, you should inform your doctor about it as it may increase prothrombin time (PT). Moreover, give a complete list of all the ongoing medications. The liver function test is also done as a part of the pre-surgery test profile to check your fitness.

The results of the liver function test are based on the analysis of a blood sample. All the tests under the liver function test are carried out with a single sample.

Test Preparation

The liver function test is a blood test that may require a fasting blood sample (fasting of 10-12 hours). The usual way to collect a blood sample is by drawing it from one of the veins. The most prominent vein is the one in the forearm of a person. The LFT procedure usually lasts for 5-10 minutes. You can continue with routine activity after the test.

Test inclusions: What parameters are included?

The liver function test includes the following parameters:

• Transaminases

Aspartate (AST or SGOT) and alanine (ALT or SGPT) are enzymes present in large quantities in the liver. ALT is an enzyme primarily present in the liver. In comparison, AST is an enzyme released from the heart, liver, skeletal muscle and kidney.

Serum levels of ALT and SGOT are increased on damage to the tissues producing them. Thus, serum estimation of SGPT is specific for liver diseases. In contrast, SGOT levels may rise in case of muscle or liver cell injury.

• Gamma-Glutamyl Transpeptidase (GGT)

The primary source of this enzyme is the liver. Elevation of GGT occurs in cholestasis (a condition where bile flow from the liver is blocked or stopped) and liver diseases. GGT levels are often high in patients with alcohol abuse.

• Albumin 

Albumin is a protein that is synthesised in the liver. It performs various functions such as providing nourishment to tissues and transporting of vitamins, hormones, medications and other substances. The blood level of albumin is decreased in extensive liver damage or disease.

• Bilirubin

Bilirubin is a waste product made by the liver after the breakdown of red blood cells. Bilirubin is excreted in the stool via the liver. Elevated bilirubin level indicates liver disease or damage or certain types of anaemia.

• Alkaline Phosphatase (ALP)

Serum alkaline phosphatase is found in the liver, bone, intestine and placenta. High ALP levels can mean cholestasis (partial or complete bile duct obstruction), bone regeneration, pregnancy and neoplastic, infiltrative and granulomatous liver diseases.

• Globulin

• Albumin/Globulin Ratio

• Proteins

• SGOT/SGPT Ratio

There are a wide variety of markers used to assess liver functionality, damage or disease. However, the markers mentioned above are extensively used. These LFT values provide an idea about the functioning and determine the extent of liver disease or damage. The liver function test result is not expressed as positive or negative. If the value is on the higher side or lower side, it indicates a liver disorder.

Certain enzyme levels are marginally higher in children, especially infants. Moreover, there may be a minimal difference in the normal LFT values between males and females.  

The normal values, parameters, and reference ranges of the test may vary from lab to lab. Please refer to the ranges mentioned in the report and consult a doctor to understand the interpretation of lab reports.

If one or more biomarkers of the liver function test are abnormal, it might indicate liver damage or disease. Liver damage can be caused by various conditions such as hepatitis, alcoholic liver disease, liver cancer, diabetes, liver cirrhosis or jaundice.

The test result may indicate liver damage or disease; however, it may not precisely pinpoint the condition. But it does help your physician to determine the next steps.

If you heavily consume alcohol, your doctor will advise you to stop drinking. Or, if you are consuming any medication causing elevation of liver biomarkers, your physician may substitute them or stop them completely.

Your doctor may decide to investigate further for hepatitis or other infections or diseases that may affect your liver. They may advise you to undergo imaging tests such as ultrasound (USG), CT scan or recommend a liver biopsy.

Jaundice, Anaemia, Cirrhosis, Gallbladder disease

The price of an LFT(Liver Function Test) can differ based on the city and the laboratory. Typically, an LFT test falls within the range of INR 400 to INR 1200. For a better understanding, here is the average cost of a LFT in some major cities in India: