When should you do a Liver Function Test (LFT)? Dr Pranav Kabra shares the A to Z of LFT

MUMBAI: A Liver Function Test or LFT in medical parlance is used to screen for liver infections, such as hepatitis or monitor the progression of a disease, such as viral or alcoholic hepatitis, and determine how well a treatment is working. It also measures the severity of a disease, particularly scarring of the liver also known as liver cirrhosis. In this exclusive interview, Dr Pranav Kabra (MD, Physician) with the Raksha Multispeciality Hospital at Malad West  in suburban Mumbai, answers pertinent questions concerning liver function tests.

What is a Liver Function Test?

A liver function test is one of a group of tests that check levels of certain enzymes and other proteins in your blood.

Some of the tests look for enzymes that you’d find in your blood only when your liver is damaged or has a disease. Others check that the organ is working the way it should.

Your liver does all kinds of work that’s crucial for your health. It helps break down food, clean your blood, make proteins, and store energy. If something goes wrong with it, you might have a number of symptoms, from yellow skin to slurred speech. That’s when you might need a liver test.

An LFT is a diagnostic tool used to detect whether a person’s liver is damaged, and can also be a screening tool for measuring the severity and type of liver disease.

Liver function is measured with a series of blood tests, called a panel. In a standard liver panel, liver enzyme tests measure levels of alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP), and gamma-glutamyl transpeptidase (GGT). Increased levels of ALT and AST can be a sign of liver damage, while increased levels of ALP and GGT can be a sign of bile duct or liver damage.

Liver protein tests measure total protein, which consists of measuring levels of globulin, prothrombin and albumin; low levels of these proteins in a person’s blood can indicate liver damage. Globulin aids the immune system with fighting infections, prothrombin aids in blood clotting, and albumin levels show whether the liver is producing a normal level of proteins.

A liver panel will also measure bilirubin levels in a person’s body to determine the severity of liver damage. During advanced stages of liver damage, bilirubin can leak out of the liver and cause jaundice, turning the urine dark and eyes yellow.

Before an LFT, your doctor will advise you not to consume certain foods or drinks that could potentially affect the results. These include over-the-counter medicines and herbal supplements. The results of an LFT can vary depending on factors such as age and gender.

Should a liver function test be done on empty stomach? Does one need to fast before doing a LFT?

Measurements of kidney, liver, and thyroid functions, as well as blood counts, are not influenced by fasting and can be done even after meals. However, fasting is required before commonly ordered tests for glucose (blood sugar) and triglycerides (part of the cholesterol, or lipid, panel) for more accurate results.

What are the signs of liver disease or damage? When should I do a LFT?

The signs of liver disease or liver damage are as follows. Any of the following symptoms (besides others) necessitate immediate medical attention and one must test for liver failure.

• Jaundice or yellowing of the eyes or skin
• Pain and distention of the abdomen due to the release of fluid from the liver
• Swelling of the lower legs due to fluid retention
• Confusion or forgetfulness. When the liver isn’t functioning properly, toxins build up in the blood and can travel to the brain, affecting brain function.
• Dark-colored urine
• Pale-colored stool
• Chronic fatigue
• Nausea or vomiting

At what age do liver problems start?

“The scary thing is that some patients are only in their 30s and 40s. The chances of developing liver disease go up the longer a person has been consuming alcohol and is most common between the ages of 40 and 50. Other doctors have diagnosed people with liver disease even when they are in their 20s. As per the latest medical updates, even a 20-year-old could be suffering from some form of liver disease or damage and needs to get tested if any of the above signs or symptoms are visible or existent.