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

Everything About Liver Function Tests- Purpose & Significance

  • WhatsApp share link icon
  • copy & share link icon
  • twitter share link icon
  • facebook share link icon

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.

Read Blog
Pale skin

Pale Skin Symptoms: Causes, Health Conditions, and When to Seek Medical Care

Skin colour provides important clues about internal health. When the skin becomes noticeably lighter than usual, it may indicate an underlying medical condition. Pale skin symptoms, also referred to as pallor, are commonly associated with reduced blood flow, low hemoglobin levels or impaired oxygen delivery to tissues.

In India, pale skin is frequently linked to anemia, nutritional deficiencies and chronic illnesses, making early recognition essential.

 

What Is Pale Skin?

Pale skin refers to:

  • lighter-than-normal skin tone

  • reduced redness

  • pale appearance of lips, gums or nail beds

It can affect the entire body or specific areas such as the face or hands.

Common Pale Skin Symptoms

Typical signs include:

  • pale face or complexion

  • pale lips or tongue

  • light-colored gums

  • pale nail beds

  • cold hands and feet

  • fatigue and weakness

These symptoms often occur together.

 

Most Common Causes of Pale Skin

Anemia

Anemia occurs when hemoglobin levels are low.

This reduces oxygen delivery to tissues, causing:

  • pale skin

  • fatigue

  • breathlessness

  • dizziness

NFHS-5 reports anemia affects a large proportion of Indian adults, especially women.

 

Iron Deficiency

Iron deficiency is the leading cause of anemia.

Contributing factors include:

  • poor dietary intake

  • blood loss

  • absorption problems

ICMR identifies iron deficiency as a major public health issue.

 

Poor Blood Circulation

Reduced circulation causes:

  • less blood reaching the skin

  • visible pallor

Conditions such as heart disease or shock impair circulation.

 

Acute Blood Loss

Sudden blood loss from:

  • injury

  • gastrointestinal bleeding

  • heavy menstrual bleeding

can cause rapid pallor and weakness.

 

Chronic Diseases

Chronic illnesses such as:

  • kidney disease

  • liver disease

  • cancer

often cause anemia and pallor over time.

 

Infections and Inflammation

Severe infections cause:

  • blood vessel constriction

  • redistribution of blood flow

This leads to pale or clammy skin.

 

Nutritional Deficiencies

Deficiencies of:

  • vitamin B12

  • folate

affect red blood cell production and cause pallor.

 

Hormonal Imbalance

Conditions like hypothyroidism reduce metabolic activity, causing:

  • pale, dry skin

  • fatigue

Thyroid disorders are common but underdiagnosed.

 

Genetic Conditions

Inherited disorders such as thalassemia affect hemoglobin production, leading to chronic pallor.

 

Pale Skin in Children and Older Adults

Children:

  • may develop pallor due to iron deficiency or infections

Older adults:

  • often develop pallor due to chronic disease or nutritional deficiency

Both groups need careful evaluation.

 

Warning Signs That Need Immediate Medical Attention

Seek urgent care if pale skin is associated with:

  • sudden weakness

  • chest pain

  • breathlessness

  • fainting

  • rapid heartbeat

These may indicate serious medical emergencies.

 

How Pale Skin Affects Daily Life

Persistent pallor often causes:

  • low energy

  • reduced physical endurance

  • difficulty concentrating

Quality of life may decline without treatment.

 

Diagnostic Evaluation

Doctors may recommend:

  • complete blood count

  • iron studies

  • vitamin B12 and folate levels

  • kidney and liver function tests

Identifying the cause is critical for treatment.

 

Role of Preventive Health Checkups

Preventive screening helps detect:

  • early anemia

  • nutritional deficiencies

  • chronic disease

Early treatment prevents complications.

 

Management and Treatment Options

Treatment depends on cause and may include:

  • iron or vitamin supplementation

  • treatment of underlying disease

  • dietary correction

  • medical therapy for chronic conditions

Self-treatment without diagnosis should be avoided.

 

Lifestyle Measures to Prevent Pallor

Helpful strategies include:

  • balanced diet rich in iron and vitamins

  • adequate hydration

  • regular health monitoring

  • treating infections early

Lifestyle changes support long-term health.

 

Importance of Early Detection

Ignoring pale skin delays diagnosis of:

  • anemia

  • internal bleeding

  • chronic illness

Early recognition improves outcomes.

 

Conclusion

Pale skin symptoms are more than a cosmetic concern. They often signal anemia, poor circulation, nutritional deficiencies or underlying medical conditions. While temporary pallor may occur due to minor causes, persistent or sudden pale skin requires medical evaluation. Early diagnosis, preventive health screening and appropriate treatment can restore normal skin tone, improve energy levels and protect long-term health.

 

References

  • Indian Council of Medical Research (ICMR) – Anemia and Nutritional Deficiency Reports

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

  • World Health Organization (WHO) – Anemia and Circulatory Health

  • Lancet – Pallor, Anemia and Chronic Disease Research

  • NITI Aayog – Preventive Healthcare and Early Symptom Detection

See all

Live Doctor consultation
Live Doctor Chat

Download Our App & Get Consultation from anywhere.

App Download
call icon for mobile number calling and whatsapp at secondmedic