A liver function test known as LFT is a blood test in which various enzymes, proteins, and other substances and particles are measured produced by the liver.

As the name says, this blood test is done to check the performance of the liver. This test monitors the overall health of the liver and how well it's functioning.

Not only this, but LFT is also important to monitor the clearing of bilirubin which is a waste product and harmful to the liver.

Liver function tests are usually ordered when someone has symptoms that suggest they may have a liver problem, such as fatigue, nausea, vomiting, abdominal pain, or dark urine.

They may also be ordered if someone has a history of liver disease or is taking medications that can cause liver damage.

Reasons to do LFT:

Liver function tests have a lot of uses. It is used to

  • Check for liver infections like hepatitis.
  • Determine the effectiveness of treatment and the progression of a disease, such as viral or alcoholic hepatitis
  • Determine the severity of the disease, particularly liver scarring called cirrhosis.
  • Keep an eye out for potential medication side effects.

How is LFT Done?

The procedure of LFT is very smooth. It does not require much hassle.

A blood sample is taken from the vein of your arm through sterilised injection.

Once the blood sample is collected, you may feel pain or discomfort from the injection needle.

Risks of Test:

This test has no serious risks or after-effects as it only requires your blood sample.

However, you may feel some swelling or bruising on the arm from where blood is taken. It is entirely normal, and it goes in a few hours or a day.

Precautions for Test:

Sometimes the readings of tests may fluctuate if you eat something or take any medicine.

In such cases, your doctors advise you not to have something to eat or to avoid your medications. Once your test is done, you can eat or drink anything you want.

But it's not always the same; sometimes, your test is done either way.

Time Taken for Results:

LFT is a quick blood test. Once your blood sample is taken for the test, it is sent straight to the laboratory.

If your laboratory is near your hospital or doctor's clinic or within the hospital, you only get the results within a few hours.

But if it is out of your reach and far from the hospital, it takes a few days.

However, this condition occurs significantly less because now, most results are shared online on the laboratory website. You can check there.


How to Interpret the Results and Take Action

If you've ever had a liver function test, you know how confusing the results can be. What do all those numbers mean? What's normal and what's not?

Here's a quick guide to help you interpret your results and take action.






Serum Bilirubin Total

Bilirubin is a yellowish pigment found in bile and is a breakdown product of normal heme catabolism.

The regular reading of serum bilirubin total lies between 0.3 and 1.0 milligrams per deciliter (mg/dL).

If your serum bilirubin total is high, it can indicate some problem in your liver or gallbladder. It can also signify Jaundice, Anemia, Liver Cirrhosis, Alcoholic liver disease, Gallstones or even a reaction to any medication

Serum Bilirubin Indirect

This is the bilirubin formed because of red blood cell breakdown. It goes from the blood to the liver.

The normal reading for Serum Bilirubin Indirect is under 0.8 mg/dL



If your serum bilirubin indirect is high, it can indicate Liver cirrhosis or fatty liver disease, Gilbert’s syndrome, or Heavy physical activity.

Serum Bilirubin Direct:

This is bilirubin after it has passed through the liver and undergone a chemical change. It travels to the intestines before passing out in your stool.

The normal reading for Serum Bilirubin Direct is under 0.2 mg/dL


If your serum bilirubin Direct is high, it can indicate some problem in your liver or gallbladder. It can also signify Liver Cirrhosis, Alcoholic liver disease, Gallstones or pancreatitis

Aspartate Aminotransferase (AST/SGOT)

Aspartate Aminotransferase, also pronounced AST is an enzyme that aids in the metabolism of amino acids.

The normal reading for AST/SGOT is under 50 IU/L


The High AST/SGOT can be due to Fatty liver, drinking alcohol, excess consumption of paracetamol, obesity, heart attack or hepatitis A, B or C.


Alanine Aminotransferase (ALT/SGPT)


Alanine Aminotransferase, just like others, is also an enzyme that is responsible for the energy of your liver. It helps in converting protein into fuel for the proper functioning of your liver.

The normal range for (ALT/SGPT) under 50 U/L



The High ALT/SGPT can be due to Fatty liver, drinking alcohol, excess consumption of paracetamol, obesity, heart attack or hepatitis A, B or C.


Alkaline Phosphatase (ALP)

Alkaline phosphatase ALP is an enzyme found not only in livers but also in bones. This enzyme-like ALP is also responsible for breaking down proteins in the liver and bones.

The normal reading for Alkaline Phosphatase is between 30 to 120 IU/L.

If Alkaline Phosphatase levels are high, it may indicate liver disorder or bone disorder.


Gamma Glutamyl Transferase (GGT)

Gamma Glutamyl Transferase GGT is an enzyme found in the whole body. However, these are present all over the body, slightly more in the liver. Like other enzymes, these leak into the blood when some damage happens to the liver.

The normal range for GGT is 5 to 55 U/L for adults.

 If GGT levels are high, it may be Liver, bile duct damage or excess consumption of alcohol.





Albumin is a protein present in your body. These proteins are present in the liver to fight against various infections; hence these are very important.

The normal range for albumin is between 3.5 to 5.2 g/dl

If Albumin levels are high, it may be due to dehydration or severe diarrhea




SGOT/SGPT Ratio helps to find out the extent of liver disease 

The average SGOT/SGPT ratio is from 0.7 to 1.4


An SGOT/SGPT ratio higher than 1.4 indicates alcoholic hepatitis and cirrhosis. It occurs in 70% of these patients, 26% of those with postnecrotic cirrhosis, 8% with chronic hepatitis and 4% with viral hepatitis.



What if the LFT results are high?

If LFT results are high, there is some damage to the liver, which is more likely to be fatty liver. LFT is also done to indicate alcohol consumption in your body and how much it has already affected the liver.

You should book a consult with a doctor to further analyze the cause of the elevated levels. Your doctor might also suggest an ultrasound scan, CT scan or a liver biopsy for finding out the extent of the liver disease.

The Bottom Line

The liver is one of the most important organs in your body. It does so many things for you, like breaking down hormones and processing proteins.

But sometimes, people do not realize when their liver's functioning is compromised due to illness or disease.

That's why liver function tests are important - they can help your doctor detect problems early on.