• 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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Tuberculosis

Tuberculosis Symptoms and Treatment: Early Signs, Diagnosis, and Recovery

Tuberculosis (TB) is one of the oldest known infectious diseases and continues to be a major public health concern, especially in developing countries. India accounts for a significant proportion of global TB cases, despite advances in diagnosis and treatment. The good news is that tuberculosis is preventable, treatable and curable when detected early and managed properly.

Understanding tuberculosis symptoms and treatment is critical for reducing disease spread, preventing complications and achieving complete recovery.

 

What Is Tuberculosis?

Tuberculosis is an infectious disease caused by Mycobacterium tuberculosis. It primarily affects the lungs (pulmonary TB) but can also involve other parts of the body such as:

  • lymph nodes
     

  • bones and joints
     

  • kidneys
     

  • brain
     

TB spreads through the air when an infected person coughs, sneezes or speaks.

 

Why Tuberculosis Remains a Major Health Issue

According to the World Health Organization and ICMR data:

  • millions of new TB cases are reported annually
     

  • delayed diagnosis increases transmission
     

  • incomplete treatment leads to drug resistance
     

Early detection and treatment are key to TB control.

 

Common Tuberculosis Symptoms

TB symptoms often develop gradually and may be mild in the early stages, leading to delayed diagnosis.

Persistent Cough

A cough lasting more than two to three weeks is a hallmark symptom of pulmonary TB.

The cough may:

  • be dry or productive
     

  • worsen over time
     

  • sometimes produce blood
     

 

Fever and Night Sweats

Low-grade fever, especially in the evenings, is common.

Night sweats that soak clothing or bedding are a classic TB sign.

 

Unexplained Weight Loss

TB increases metabolic demand and reduces appetite, leading to significant weight loss.

 

Fatigue and Weakness

Persistent tiredness and reduced stamina occur due to chronic infection.

 

Chest Pain

Chest discomfort or pain may occur during coughing or breathing.

 

Symptoms of Extra-Pulmonary TB

When TB affects organs outside the lungs, symptoms depend on the site involved and may include:

  • swollen lymph nodes
     

  • bone or joint pain
     

  • headaches or neurological symptoms
     

  • urinary issues
     

 

Why TB Symptoms Are Often Ignored

Many TB symptoms resemble common infections or general weakness.

This leads to:

  • delayed medical consultation
     

  • prolonged transmission
     

  • disease progression
     

Awareness improves early detection.

 

How Tuberculosis Is Diagnosed

Diagnosis involves a combination of:

  • sputum tests
     

  • chest X-ray
     

  • molecular tests such as CBNAAT
     

  • blood tests and imaging for extra-pulmonary TB
     

Early and accurate diagnosis is essential for effective treatment.

 

Tuberculosis Treatment Explained

TB treatment involves a combination of antibiotics taken over a fixed duration.

Standard TB Treatment

For drug-sensitive TB, treatment typically lasts:

  • 6 months
     

The regimen includes multiple antibiotics taken in phases to ensure complete bacterial clearance.

 

Importance of Treatment Adherence

TB bacteria are slow-growing and resilient.

Stopping treatment early can result in:

  • incomplete cure
     

  • relapse
     

  • drug-resistant TB
     

Completing the full course is essential.

 

Drug-Resistant TB

If TB bacteria become resistant to standard drugs, treatment becomes longer and more complex.

Drug-resistant TB requires:

  • specialised medications
     

  • longer treatment duration
     

  • close medical supervision
     

Prevention of resistance depends on correct treatment from the start.

 

Side Effects of TB Treatment

Some individuals may experience side effects such as:

  • nausea
     

  • loss of appetite
     

  • mild liver enzyme changes
     

Most side effects are manageable with medical guidance and do not require stopping treatment.

 

TB and Public Health

TB is not just an individual health issue but a community concern.

Effective TB control requires:

  • early diagnosis
     

  • treatment adherence
     

  • contact tracing
     

  • public awareness
     

India’s national TB elimination programmes focus on these strategies.

 

Preventing Tuberculosis

Preventive measures include:

  • early detection and treatment of active TB
     

  • improving nutrition and immunity
     

  • adequate ventilation in living spaces
     

  • screening close contacts
     

BCG vaccination offers partial protection, especially in children.

 

Living With and Recovering From TB

With proper treatment:

  • symptoms gradually improve
     

  • infection becomes non-contagious
     

  • normal life can be resumed
     

Regular follow-up ensures complete recovery.

 

When to Seek Medical Help

Consult a healthcare provider if experiencing:

  • cough lasting more than two weeks
     

  • unexplained weight loss
     

  • persistent fever or night sweats
     

  • blood in sputum
     

Early action saves lives and prevents spread.

 

Long-Term Outlook After TB Treatment

Most individuals who complete treatment:

  • recover fully
     

  • regain normal lung function
     

  • return to daily activities
     

Long-term complications are rare with timely care.

 

Conclusion

Tuberculosis symptoms and treatment must be understood clearly to combat this preventable and curable disease. Persistent cough, fever, night sweats and weight loss should never be ignored. Early diagnosis, complete treatment adherence and regular follow-up are essential for curing TB and preventing transmission. With proper medical care and public awareness, tuberculosis can be effectively controlled and eliminated as a public health threat.


 

References

  • Indian Council of Medical Research (ICMR) – Tuberculosis Epidemiology and Treatment Guidelines
  • World Health Organization (WHO) – Global Tuberculosis Report
  • National Tuberculosis Elimination Programme (NTEP) – Government of India
  • Lancet Infectious Diseases – TB Diagnosis and Treatment Outcomes
  • National Family Health Survey (NFHS-5) – Infectious Disease Indicators
  • Statista – Global Tuberculosis Burden and Trends

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