• 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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Why do you wake up tired

Why Do You Wake Up Tired Even After 8 Hours Sleep?

Getting 8 hours of sleep is often seen as the gold standard for good health. But what if you’re still waking up feeling groggy, exhausted, and low on energy—despite clocking in those 8 hours? If that sounds like you, you’re not alone.

In this blog, we’ll explore why you wake up tired even after 8 hours sleep, the possible reasons behind it, and simple ways to fix the issue so you can start your day refreshed and energized.

 

Sleep Quantity vs. Sleep Quality

It’s important to understand that sleep is not just about how long you sleep, but how well you sleep.

There are different stages of sleep your body goes through:

  • Light Sleep (Stage 1 & 2)
     

  • Deep Sleep (Stage 3)
     

  • REM Sleep (Stage 4) – where dreams and memory processing happen
     

If your sleep is constantly interrupted, or if you don’t get enough deep or REM sleep, your body and brain won’t be fully rested—even after 8 hours in bed.

 

7 Common Reasons You Wake Up Tired After a Full Night’s Sleep

1. Poor Sleep Quality

You may be lying in bed for 8 hours, but if your sleep is light or frequently interrupted, it won’t be refreshing. Common reasons include:

  • Noisy environment
     

  • Uncomfortable mattress or pillow
     

  • Room too hot or too cold
     

  • Lights or electronics nearby
     

Fix: Try blackout curtains, keep the room cool and dark, and follow a fixed bedtime routine.

 

2. Undiagnosed Sleep Disorders

Conditions like sleep apnea, restless leg syndrome, or insomnia can reduce sleep quality without you even realizing it.

Sleep apnea, for example, causes you to stop breathing for short periods during sleep. You may not wake up fully, but your body doesn’t get enough oxygen—leading to morning tiredness and brain fog.

Fix: If your partner says you snore heavily or you often wake up gasping for air, consult a doctor for a sleep study.

 

3. Too Much Screen Time at Night

Smartphones, laptops, and TVs emit blue light, which blocks melatonin—a hormone that helps you fall asleep.

If you scroll Instagram or binge-watch shows late at night, your brain might stay active even after you fall asleep.

Fix: Stop using screens 1 hour before bedtime. Use night mode or blue light filters if necessary.

 

4. Eating or Drinking Close to Bedtime

Heavy meals or caffeine before bed can disturb your sleep by causing indigestion, bloating, or increased alertness.

Fix: Avoid caffeine after 5 PM, and try to have your dinner at least 2 hours before sleeping.

 

5. Mental Health Issues

Conditions like stress, anxiety, or depression can impact sleep quality. You may sleep for hours but still wake up tired due to mental fatigue.

Fix: Practice stress management through:

  • Journaling
     

  • Breathing exercises
     

  • Meditation
     

  • Seeking therapy if needed
     

 

6. Vitamin or Hormonal Imbalance

Low levels of Vitamin D, Vitamin B12, iron, or thyroid dysfunction can cause constant fatigue—even with good sleep.

Fix: A simple blood test can help detect deficiencies. You can book these tests via SecondMedic.com, powered by Thyrocare, with home sample collection.

Recommended tests:

  • Vitamin D Test
     

  • Vitamin B12
     

  • Thyroid Profile
     

  • CBC (Complete Blood Count)
     

 

7. Lack of Physical Activity

Not moving your body enough during the day can lead to low-quality sleep at night. Exercise helps burn excess energy and improves deep sleep.

Fix: Aim for at least 30 minutes of physical activity, like walking, yoga, or cycling daily.

 

Signs That You’re Not Getting Good Sleep

  • You hit the snooze button multiple times
     

  • You feel sleepy by mid-morning
     

  • You wake up with a heavy head or sore body
     

  • You need coffee immediately to function
     

  • You feel irritated, anxious, or unmotivated
     

These are signs your body is not truly rested.

 

Simple Tips for Better Sleep & Morning Energy

  1. Stick to a sleep schedule: Go to bed and wake up at the same time every day—even on weekends.
     

  2. Create a sleep-friendly space: Keep your bedroom cool, quiet, and dark.
     

  3. Limit naps: Daytime naps should be less than 30 minutes and before 3 PM.
     

  4. Stay hydrated—but not too close to bedtime: Drinking too much water late may wake you up to pee.
     

  5. Practice relaxation before bed: Try reading, light stretching, or herbal tea.
     

 

Conclusion

Feeling tired despite getting enough sleep can be frustrating. But remember, quality beats quantity when it comes to sleep. By making small changes in your routine, checking for hidden health issues, and improving your lifestyle, you can wake up feeling refreshed and ready to take on the day.

If you’ve been wondering why do you wake up tired even after 8 hours sleep, now you know where to start fixing it. Begin today with a better sleep routine—and better mornings will follow.

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