• 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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Sadness is a normal emotional

Difference Between Sadness and Depression: Understanding Normal Emotions vs Mental Illness

Feeling low or unhappy is a part of being human. However, not all low moods are the same. Many people confuse sadness with depression, which can delay proper support and treatment. Understanding the difference between sadness and depression is crucial for mental health awareness, early intervention and reducing stigma.

In India, mental health conditions are often misunderstood, with emotional distress frequently dismissed as temporary sadness.

 

What Is Sadness?

Sadness is a normal human emotion.

It usually occurs due to:

  • loss or disappointment

  • relationship issues

  • failure or stress

  • temporary life challenges

Sadness serves a psychological purpose, allowing individuals to process emotions and adapt.

 

Key Characteristics of Sadness

Sadness is:

  • situational

  • temporary

  • emotionally painful but manageable

  • responsive to support and positive events

A person experiencing sadness can still function, enjoy moments and feel hopeful.

 

What Is Depression?

Depression is a medical condition classified as a mood disorder.

It affects:

  • emotions

  • thinking patterns

  • behaviour

  • physical health

According to WHO, depression is one of the leading causes of disability worldwide.

 

Core Symptoms of Depression

Depression involves a combination of symptoms such as:

  • persistent low mood

  • loss of interest or pleasure

  • fatigue

  • sleep disturbances

  • appetite changes

  • feelings of worthlessness

  • difficulty concentrating

These symptoms last at least two weeks or longer.

 

Duration: A Key Difference

One major difference lies in duration.

Sadness:

  • lasts hours or days

  • improves with time

Depression:

  • lasts weeks or months

  • persists despite positive events

Duration helps distinguish emotional response from illness.

 

Impact on Daily Functioning

Sadness:

  • allows continuation of work and relationships

  • may reduce motivation temporarily

Depression:

  • interferes with work, studies and relationships

  • reduces self-care and productivity

Functional impairment is a defining feature of depression.

 

Emotional Experience: Sadness vs Depression

Sadness:

  • allows emotional range

  • moments of joy still occur

Depression:

  • creates emotional numbness

  • joy and interest disappear

People with depression often describe feeling empty rather than sad.

 

Physical Symptoms in Depression

Depression is not only emotional.

Physical symptoms include:

  • chronic fatigue

  • body aches

  • headaches

  • digestive issues

ICMR mental health studies highlight the physical burden of depression.

 

Thought Patterns and Self-Perception

Sadness:

  • thoughts remain realistic

  • self-worth is preserved

Depression:

  • negative self-talk dominates

  • feelings of guilt and worthlessness increase

These cognitive changes deepen emotional suffering.

 

Risk Factors for Depression

Factors increasing depression risk include:

  • chronic stress

  • trauma

  • family history

  • medical illnesses

  • hormonal changes

NFHS-5 data indicates rising mental health concerns among young adults.

 

Can Sadness Turn Into Depression?

Yes, prolonged or unresolved sadness can progress into depression.

This is more likely when:

  • stressors are ongoing

  • support systems are weak

  • coping mechanisms are limited

Early emotional support can prevent progression.

 

When to Seek Professional Help

Seek help if:

  • low mood lasts more than two weeks

  • daily functioning is affected

  • sleep and appetite are disturbed

  • thoughts of self-harm occur

Early care leads to better outcomes.

 

Treatment Differences

Sadness:

  • improves with rest, support and time

Depression:

  • requires psychotherapy

  • may need medication

  • benefits from structured care

WHO emphasises early treatment to reduce disability.

 

Role of Social Support

Support systems help both conditions but are essential for recovery.

Depression recovery improves with:

  • understanding family

  • supportive workplaces

  • accessible mental healthcare

Stigma reduction is key.

 

Mental Health Awareness in India

Mental health remains underdiagnosed in India.

NITI Aayog reports:

  • limited access to mental health services

  • low awareness

  • high stigma

Education helps bridge this gap.

 

Importance of Early Recognition

Recognising depression early:

  • prevents worsening

  • reduces suicide risk

  • improves quality of life

Delay increases suffering and complications.

 

Supporting Someone With Depression

Helpful actions include:

  • listening without judgement

  • encouraging professional help

  • avoiding minimising feelings

Compassion is more effective than advice.

 

Conclusion

Understanding the difference between sadness and depression is essential for emotional wellbeing and mental health care. Sadness is a natural, temporary response to life events, while depression is a serious medical condition that affects thoughts, emotions and daily functioning. Recognising the signs early and seeking appropriate help can prevent long-term suffering and promote recovery. Mental health deserves the same attention and care as physical health.

 

References

  • World Health Organization (WHO) – Depression and Mental Health Disorders

  • Indian Council of Medical Research (ICMR) – Mental Health Research and Burden

  • National Family Health Survey (NFHS-5) – Mental Health Indicators

  • Lancet – Depression, Disability and Public Health

  • NITI Aayog – National Mental Health Policy and Awareness Reports

  • Statista – Global and Indian Mental Health Trends

See all

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