About Liver Function Test:
Liver is one of the most important organs in the body. It does a wide range of tasks to keep the body healthy and going. These tasks would include breaking down food and helping in the digestion, cleaning the blood, storing energy and also making proteins. However, due to some disease or some other problems, the liver may not work properly or as it should be. Depending on the symptoms that you may have, your doctor will recommend that you undergo some tests that will measure your blood enzymes levels, proteins levels etc. This will help the doctor to understand the extent of damage that has been caused to the liver and also identify the disease that you are suffering from.
There is not just a single test that can be termed as a liver function test, but an array of tests that in total can tell whether the liver is functioning properly or not. The liver functions test either tells you if the liver is producing the enzymes and proteins and other such chemicals that it is supposed to produce properly or if there is anything wrong with the liver. Any abnormality in liver function test results does not mean that the person is suffering from a certain disease. The doctor will be able to tell you the actual scenario, based on the test results.
Why is Liver Function Test Done?
As already mentioned, the liver may not function properly, if you have some disease or disorder. In that case, it is a must that the disease is identified at an earliest, to prevent further damages caused to the liver. The general symptoms that indicate the need to undergo liver function tests are –
- Yellowish eyes and skin
- Light coloured stool
- Dark coloured urine
- Feeling like vomiting
- Swelling in the belly
- Loss of appetite.
All these symptoms indicate the possibility of some diseases such as hepatitis B or C, cirrhosis of liver, jaundice etc. However, along with the presence of these symptoms, there are some other cases as well that will need you to undergo the liver function test. These are –
- If you are alcoholic or a heavy drinker
- If you are pregnant or planning to have a pregnancy
- If you are taking medicines that are harmful for the liver
- If you are already suffering from some diseases such as high blood pressure or diabetes
- If you are overweight
- If you already have a liver disease and undergoing a treatment, the liver function test will tell if the treatment is going well.
What Does The Value (High/Low) of Liver Function Test Indicate?
There are many liver function tests that the doctor might tell you to undergo, if you have any symptom associated with dysfunctional or damaged liver. They have different complex names. The test results can indicate low or high levels of a certain chemical in the blood and thus, indicate the liver disease that you may have.
What Does High or Low Values of Alanine Transaminase (ALT) Test Indicate?
The ALT is an enzyme test that indicates whether you have damage in your liver or not. The ALT or Alanine transaminase is an enzyme that breaks down proteins that the liver makes. However, if there is damage in the liver, the ALT is released into the blood. The normal range for ALT is 7–55 units per litre (U/L). If the ALT test indicates a high level of ALT in the blood, it will indicate damage in the liver. However, if the level is low, it does not indicate any disease or problem.
What Does Albumin and Total Protein Level in LFT Indicate?
The liver produces a number of proteins such as albumin, globulin etc. The normal range for albumin is 3.5–5.0 grams per decilitre (g/dL). If the blood does not have enough of these proteins, or a low level of albumin and globulin, it would mean that there is damage caused to the liver.
What Does High or Low Values of Bilirubin in LFT Indicate?
The normal range for bilirubin is 0.1–1.2 milligrams per deciliter (mg/dL). High level of bilirubin indicates jaundice. When red blood cells are broken, bilirubin is made. The liver helps to clear this out from the body. The bilirubin test indicates liver damage and jaundice.
Aspartate Transaminase (AST) Test
Aspartate transaminase is an enzyme that the liver secretes. The normal range for bilirubin is 0.1–1.2 milligrams per decilitre (mg/dL). When the liver makes too much of this enzyme, it indicates liver damage. However, low level of AST is not problematic for the body.
Gamma-glutamyltransferase (GGT) Test
This test would indicate damage to the liver or the bile duct.
Prothrombin Time (PT) Test
When there is a cut and blood shed, it is a must that the blood clots as soon as possible. Otherwise, it would lead to serious illness. The prothrombin helps in this blood clotting. However, when the blood takes longer than usual to clot, it indicates liver damage. PT test will tell the low level of prothrombin and this will mean that there is some problem in the liver.
L-lactate Dehydrogenase (LD) Test
High levels of LD in LFT can also indicate liver damage.
Alkaline Phosphatase (ALP) Test
ALP is an enzyme that can be found in the liver, bile duct and even in the bones. The normal range for ALP is 45–115 U/L. If the level is high, it will indicate blockage in the bile ducts or bone disease or liver damage. However, children and adolescents generally have a high level of ALP. On the other hand, low levels of ALP can also indicate certain conditions such as malnutrition, zinc deficiency, Wilson disease etc.
Sometimes, the doctor may tell you to undergo more than one of these tests. However, if the test results are not always in the normal range, it does not mean there is a serious trouble with the liver. It can be the result of some other conditions as well. Consult with the doctor, if you have any symptoms that indicates problem with the liver.
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