• Published on: Sep 15, 2021
  • 5 minute read
  • By: Dr Rakesh Rai

Everything About Liver Function Tests- Purpose & Significance

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Everything About Liver Function Tests- Purpose & Significance

Liver function tests are medical laboratory tests that measure the number of various substances in the blood that are released into your blood by liver cells or made by your liver. These substances are often called "liver enzymes" because they are enzymes that are produced exclusively by the liver to help regulate metabolism for processing chemicals, nutrients, and drugs.

A high level of any one of these may suggest an abnormal situation involving your liver. The most common symptoms associated with a problem involving your liver include nausea, vomiting, yellowing skin color (jaundice), fever, and abdominal discomfort such as pain on gentle pressing around about halfway down on the right side of the abdomen.

A liver function test is a blood test that evaluates an individual's liver function or sees if there may be a problem in this organ. Liver functions including leukocyte count, alkaline phosphatase, ALT/AST enzymes, and bilirubin levels are measured with results interpreted by physicians who then advise treatment options to relieve pain or reduce the risk of liver disease. If the level of these agents is elevated then the physician will typically recommend further diagnostics such as antibody testing for hepatitis B and C infections, ultrasounds, and biopsies.

Liver function tests are a series of blood tests used to evaluate liver function. Tests may include the following:

  • Inclusion of serum albumin or total proteins as variables in the SMA12 test
  • Albumin fractional catabolic rate (ACR) and erythrocyte sedimentation rate (ESR) measurements, which can be used as a surrogate marker for changes in hepatocellular activity
  • Visible change is indicative that hepatocytes have been damaged or destroyed, an indicator that liver disease is present.
  • Fractional synthetic rate of albumin synthesis calculated from measurements of serum creatinine and urinary urea nitrogen providing information about hepatocyte intracellular mass status with decreased album

The most common of these are aminotransferases ALT and AST. These enzymes are released into the bloodstream in excessive amounts by the cells that line the bile ducts that carry bile from the liver - where it gets made - to where it gets used up in digestion ??i.e., all over your body, not just in your liver but also near your kidneys) when there's any sort of problem with those cells or with damage done to them because of some other hurtful event.

In the context of a medical lab test, a liver function test is anyone that has to do with the liver. Serum bilirubin, alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase are common ones. A veterinarian could use ultrasound as well as biochemistry analysis. These tests show how well your liver is performing its duty to remove toxins from your body and to make bile for those toxins.  Liver function tests are conducted to assess the liver's ability to convert inactive substances in your blood to active ones.

Alanine aminotransferase (ALT/SGPT): tests what process - amino acid, carbohydrate, or fat - your liver is having trouble breaking down to store sugar for later use indigestion. This test will only show what type of enzyme the liver has difficulty processing at this time, so if this is normal but an alkaline phosphatase test comes back abnormal, this means there may be a different illness affecting the liver.

The test can measure certain chemicals that are released because of metabolism and excreted from the body in urine, such as albumin.

The most common indicators measured by blood-based liver function tests include GGT, ALP, total bilirubin / conjugated/unconjugated bilirubin, ALT and ASAT.

A group of enzymes found in healthy livers called GOT (gamma-glutamyl transpeptidase) and GPT (gamma-glutamyltransferase) can also be measured to determine damage to liver cells.

Liver Function Tests (LFTs) are a group of tests that measure the levels and function of various substances in the blood leave before digestion and within the liver. These include enzymes and proteins made by the liver; cholesterol, copper, iron, calcium, sodium, potassium; bilirubin level; albumin levels. The LFTs can be used to help diagnose many diseases such as viral hepatitis or alcoholic liver disease.

A history would normally prompt additional testing such as abdominal imaging for gallstones or metabolic abnormalities like cirrhosis caused by alcohol consumption. Kidney function should be tested because high-protein diets may cause kidney problems too. A genetic test might be warranted if there is a family history of inheritance. Liver function tests are a group of blood tests that doctors might use to evaluate the liver's ability to gather and store glycogen (sugar) and protein, produce bile, filter the blood, and produce cholesterol.

Drugs can accumulate in liver cells, leading to changes in levels of enzymes. Enzymes that are elevated may indicate an inflammatory or viral process as well as the use of certain medications such as steroids which need some time to clear from the body after discontinuation. The test isn't specific for any disease but can show if there is a liver problem even before symptoms occur, including cirrhosis and early hepatitis B and C infections. When first conducted, rapid elevations or decreases might be indications of acute injury or pre-clinically chronic injury respectively.

The liver may be the body's most important gland. It synthesizes nutrients from fat, carbohydrates, and protein into a form that can be absorbed by the blood to supply the cells, brain, and other tissues with a continuous supply of fuel. The liver also acts as a storage center for high-density energy reserves in times of food shortage or famine.

In response to viruses or bacteria which enter from our gut through their ingestion of contaminated water or insects’ excretions for example), substances called antibodies are manufactured in great numbers by specialized cells in an inflammatory reaction known as acute hepatitis. LFT helps measure the liver's endurance, by testing erythrocyte count, serum albumin level, bilirubin level and prothrombin time.

It's normal for your erythrocyte count to drop over time as you age. This is due mainly to the production of fewer red blood cells in your bone marrow. It may provide an indication of what is happening inside the liver with regard to the regeneration of new cells. An elevated or persistently high level can indicate cirrhosis or cancer. If it's persistently high, then requires radiologic imaging for diagnosis.

The liver function tests are blood tests that tell the physician how well the liver is working. The enzymes GGT, ALT, AST, and ALP are primarily tested to examine what should be healthy activities through three phases of hepatic metabolism. Since these enzymes exist primarily in the liver, they do not normally show up in any other tissue or fluid other than the bloodstream. If there is a disease that affects the cells within the liver, then inflammatory processes will ensue. This will lead to excessive production of oxygen-free radicals to facilitate cell death and release toxins into circulation which can affect all body systems including altering enzyme quantities, so they bump up against their normal reference ranges for evaluation.

The purpose of liver function tests is to diagnose and monitor a person's condition, based on levels of certain enzymes in the blood.

A high level of transaminases might be due to a variety of diseases or conditions, including hepatitis, cirrhosis, biliary obstruction from gallstones, or pancreatitis. Liver disease disrupting the production and release of albumin will also produce abnormally low-level albumin which can be detected with this test. A qualitative determination can be made if large amounts of Clotting Factor VIII are released into the bloodstream - Hepaetous Patina (HP) - leading to severe bleeding episodes independent from coagulation defects where plasma clotting normally should take place.

Liver function tests measure the level of different substances produced or used by the liver, such as albumin. The liver conditions may include fatty liver (hepatic steatosis), alcoholic hepatitis, cirrhosis, and many disorders affecting other parts of the body which ultimately damage the working capacity of your liver. Liver function tests are not meant to detect acute hepatitis or mild cases of elevated enzyme levels that commonly resolve on their own. Normal results suggest that there is no abnormality with your kidneys. Abnormal livers often show high amounts of creatinine kinase (CK) and alanine aminotransferase (ALT).

The liver is the body's only organ able to break down toxic compounds, so its function must be checked. The example you gave -- SGPT, or aspartate aminotransferase -- measures the level of a major liver enzyme. High levels could indicate damage from drugs also used for weight loss, such as acetaminophen/paracetamol (Tylenol) or metformin (Glucophage). Too-low levels of hepatocyte enzymes mean that the liver's not functioning properly and may develop complications like hepatitis and cirrhosis.

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Regular health

Importance of Regular Health Checkups: Early Detection Saves Lives

In today’s fast-paced lifestyle, many individuals prioritise work and family responsibilities while neglecting their own health. However, understanding the importance of regular health checkups is critical for preventing serious medical conditions. Many diseases develop silently without noticeable symptoms, making routine screening essential for early diagnosis and effective treatment.

According to the Indian Council of Medical Research (ICMR), non-communicable diseases such as diabetes, hypertension and cardiovascular conditions are rising across India. Early detection through preventive checkups significantly reduces complications and mortality.

 

What Are Regular Health Checkups?

Regular health checkups involve:

  • routine blood tests

  • blood pressure monitoring

  • cholesterol screening

  • organ function tests

  • lifestyle risk assessments

These assessments help identify abnormalities before they progress into severe conditions.

 

Why Preventive Healthcare Matters

Preventive healthcare focuses on:

  • identifying risk factors

  • detecting disease early

  • preventing complications

The World Health Organization states that preventive care reduces long-term healthcare burden and improves life expectancy.

 

Early Detection of Chronic Diseases

Diabetes

India has over 100 million people living with diabetes, according to ICMR data. Many individuals are unaware until complications arise.

Early screening detects:

  • elevated blood sugar

  • insulin resistance

 

Hypertension

NFHS-5 reports that nearly one in four adults in India has hypertension.

Regular monitoring prevents:

  • stroke

  • heart attack

  • kidney damage

 

Heart Disease

Cholesterol screening identifies risk before symptoms appear.

Timely lifestyle modifications reduce cardiovascular events.

 

Cancer Screening and Survival Rates

Screenings such as:

  • mammograms

  • Pap smears

  • colon cancer screening

significantly improve survival when disease is detected early.

 

Monitoring Organ Function

Regular checkups assess:

  • liver health

  • kidney function

  • thyroid levels

Silent organ dysfunction can be detected early.

 

Benefits of Regular Health Checkups

Reduced Healthcare Costs

Treating advanced disease is more expensive than preventive care.

 

Improved Quality of Life

Early treatment reduces long-term complications.

 

Peace of Mind

Knowing health parameters are normal reduces anxiety.

 

Better Lifestyle Decisions

Screening results motivate healthier habits.

 

Who Should Get Regular Health Checkups?

  • adults above 30 years

  • individuals with family history of chronic disease

  • smokers

  • overweight individuals

  • sedentary professionals

High-risk groups may require more frequent testing.

 

Frequency of Health Screenings

General recommendation:

  • Annual checkup for adults

  • Biannual or quarterly monitoring for high-risk individuals

Doctors personalise schedules based on medical history.

 

Corporate Health Checkups

Many organisations conduct:

  • workplace screening camps

  • employee wellness programs

These initiatives improve workforce productivity and reduce absenteeism.

 

Preventive Health in India

NITI Aayog highlights preventive healthcare as essential for reducing national disease burden.

Increasing awareness about routine checkups is critical.

 

Common Tests in Annual Health Packages

  • Complete blood count

  • Lipid profile

  • Fasting blood sugar

  • HbA1c

  • Liver function test

  • Kidney function test

  • Thyroid profile

  • Vitamin levels

These tests provide comprehensive health insight.

 

Addressing Common Misconceptions

Many people avoid checkups because:

  • they feel healthy

  • they fear results

  • they lack time

However, absence of symptoms does not mean absence of disease.

 

Lifestyle Diseases and Urbanisation

Urban lifestyles contribute to:

  • sedentary behaviour

  • poor diet

  • stress

Regular monitoring counters these risks.

 

Digital Health and Screening Accessibility

Online booking platforms and home sample collection make preventive care more accessible and convenient.

Technology supports proactive health management.

 

Building a Culture of Preventive Health

Encouraging:

  • annual screenings

  • family health awareness

  • workplace initiatives

creates healthier communities.

 

Conclusion

Understanding the importance of regular health checkups is essential for preventing chronic disease and improving life expectancy. Early detection of diabetes, hypertension, heart disease and other conditions allows timely treatment and reduces complications. Preventive healthcare is not an expense but an investment in long-term wellbeing. Scheduling routine screenings today can protect health and save lives tomorrow.

 

References

  • Indian Council of Medical Research (ICMR) – Non-Communicable Disease Reports

  • National Family Health Survey (NFHS-5) – Adult Health Data

  • World Health Organization (WHO) – Preventive Healthcare Guidelines

  • NITI Aayog – National Health and Preventive Strategy Reports

  • Lancet – Early Detection and Disease Prevention Studies

See all

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