Liver Function Tests: What You Should Know

What is a liver functioning test?

Liver function tests are essentially blood tests. These tests are prescribed to detect malfunctions in the liver, a vital reddish-brown organ in the digestive system. The liver is responsible for regulating blood circulation and metabolism in addition to acting as a remover of toxins in the blood. 

The detection is done by measuring the status of liver enzymes alongside bilirubin, a yellow pigment formed when RCBs are broken down in the liver, in the blood serum. The results from the liver functioning test form the basis of diagnosis for liver disease, although they do not indicate what liver dysfunction occurred.

Why is the LFT test important?

The liver is the lifeline of a person. It has enzymes that help in the metabolism of fats and proteins. The liver spleen is crucial for regulating the haemoglobin levels of the blood. Liver dysfunction can be fatal for the person and hence detected via LFT test at the earliest.

Today alcohol and drug consumption have increased drastically. Due to the fast-paced lifestyle, people are becoming obese too. Consequently, the population is becoming more and more vulnerable to liver diseases.

The situation worsens since the early stages of liver dysfunction do not have any symptoms. As a result, taking preventive measures on time becomes hard.

A liver functioning test can detect liver dysfunction even before symptoms surface. Hence getting one if you find yourself vulnerable is crucial. Otherwise, persistent liver damage can cause cirrhosis and eventually lead to death. 

When are liver function tests prescribed? 

A physician suggests taking a liver functioning test for several diseases like:

• Hepatitis A, B, and C
• Liver disorders
• Hypertension
• Liver cirrhosis or failure

Furthermore, the test is prescribed when vulnerable to developing liver infections. 

These circumstances include:

• Obesity
• Alcoholism or any substance abuse
• Family history of liver diseases
• Genetic disorders. Especially in the case of alpha 1AT deficiency.
• Drugs used to contain HIV can cause side effects in the liver. Thus, if somebody has HIV, they ought to observe the side effects on a routine basis.
• Medicines: Antifungal drugs, steroids, niacin, and medicines that have methotrexate or azathioprine can have side effects on the liver. 
• Diseases: Diabetes, anaemia, gall bladder dysfunction.

A liver functioning test is prescribed by the doctor when you show symptoms like:

• Vomiting bile or blood.
• Weakness along with dizziness and fatigue
• Sudden loss in weight.
• Excruciating pain in the abdomen or belly.
• Yellow eyes and skin.
• Dark urination
• Diarrhoea

After the test results are out, you must immediately see your doctor for further evaluation.

What happens in an LFT?

A Liver function test involves taking a blood sample first. When you reach the laboratory or hospital, the staff member would get you seated and attach a band to the upper arm at the joint. A sterilized needle is used to extract a few ml of blood from your vein, and the sample is put into a vial. 

From here, the sample is tested to measure the levels of different substances like:

• Albumin: This is a protein that is made by the liver. It is functional in transporting vitamins and enzymes, as well as hormones via the bloodstream.
• Enzymes, such as alkaline phosphatase, alanine transaminase, and gamma-glutamyl transferase, are produced by the liver.
• Lactate dehydrogenase, an enzyme formed in reaction to damage to the body.
• Prothrombin time or PT. This is a type of protein used during blood clotting.

When blood is extracted, you might feel a slight sting caused by the needle. Otherwise, the test has no complications. Some people, however, might feel a bit lightheaded for some time. In such a situation, you must sit at the facility before taking your leave for home.

What can high levels of each substance indicate?

High levels of these substances indicate:

• Alanine transaminase and Aspartate aminotransferase: Liver damage
• Alkaline phosphatase: Liver inflammation, blockage of bile ducts, bone disease.
• Bulbirin: Compromised liver function or mononucleosis
• Gamma-glutamyltransferase: Liver damage and/or bile duct damage.
• PT: Compromised liver function, blood clotting disorder, or Vitamin K deficit. 

Furthermore, low albumin levels are a sign of cirrhosis, liver infection, and liver inflammation alongside kidney disease.

What do you need to know/do before the test?

• Before taking the test, you will be asked to fast for at least 8 hours. Hence, it is the wisest to go in the morning after you wake.
• The test takes the blood sample from the upper arm. Hence, wearing half-sleeved attire will be convenient. If it is winter, wear something warm over a half sleeve shirt/T-shirt.
• The needle might sting if you are too stressed. Hence, keep calm so that your muscles can relax and hurt less. This will also make the process smoother. If you are afraid of needles, you can always revert or close your eyes.
• The doctor might ask you to abstain from taking medications before the test.

Is the test risky?

The test is harmless and does not involve any health risks. However, you might get infected if the equipment used for extracting blood is not sterilized well. Hence, it is crucial to choose a reputed facility.