Understanding the Basics of Liver Function Tests

The liver is one of the most important organs in the body playing a key role in maintaining our overall health. Located beneath the diaphragm, the liver performs a variety of functions including regulating most chemical levels in the blood, detoxification, metabolism, and production of essential proteins. The liver is also important when it comes to regulating red blood cells (RBCs), glucose synthesis and storage. It also metabolizes drugs and alcohol and forms them into parts which are easier to use for the rest of the body or that are nontoxic. 

 

To check out if the liver is functioning optimally, liver function tests (LFTs) are done. These are simple blood tests that evaluate different enzymes and substances made by the liver.

 

What are the symptoms related to liver disease?

 

For any treatment to start, it is important for the clinician to know the cause and extent of a liver problem. Liver diseases are difficult to detect at first because of the lack of noticeable signs and symptoms present in most people. The symptoms only appear when the liver becomes inflamed and irritated. For instance, if the disease is not detected early and lasts over a period of months and years, it can progress to cirrhosis. Here are some of the signs that indicate an issue with the organ:

 

• Abdominal pain and swelling
• Swelling in the legs and ankles
• Jaundice
• Itchy skin
• Pale stool color
• Chronic fatigue
• Nausea or vomiting
• Loss of appetite
• Dark urine color
• Tendency to bruise easily

 

You may also be recommended to go for this test if you: 

 

• Drink large amounts of alcohol
• Have liver disease or damage
• Are, or might be, infected with a hepatitis virus

 

What does the test measure?

 

The test involves multiple measurements, including: 

 

Alanine Aminotransferase (ALT): This enzyme is responsible for breaking down dietary protein into energy for the liver. Elevated ALT levels may be a sign of liver injury or disease.

 

Alkaline Phosphatase (ALP): ALP is an enzyme present in the blood that helps the liver break down proteins in the body. Higher ALP levels may stem from a possible obstruction in bile ducts, hepatitis, mononucleosis and cirrhosis.

 

Aspartate Aminotransferase (AST): It is an enzyme that exists in the liver, heart, brain, kidneys and many other tissues in the body. It is commonly associated with liver health. Those with blocked bile ducts, cirrhosis, or liver cancer are likely to show moderately raised or nearly normal AST levels. Higher AST concentrations are also observed after heart attacks and muscle injuries.

 

Bilirubin: It is an orange-yellow pigment that forms normally as a result of red blood cell break down. Higher bilirubin levels happen due to excess production or insufficient removal caused by bile duct obstructions or issues in bilirubin processing. 

 

Albumin: A significant protein produced by the liver, albumin is responsible for carrying substances such as hormones, medicines, and enzymes throughout your body. A low albumin level can indicate an issue with the liver or kidneys, malnutrition, and inflammation. 

 

Total Protein: It measures the albumin and globulin levels. It also calculates the amount of albumin you have compared to globulin, or the “A/G ratio.” Low total protein levels might suggest health concerns related to the liver or kidneys. 

 

Gamma-Glutamyl Transferase (GGT): GGT is an enzyme found mostly in the liver. Higher GGT levels can indicate a disease which could cause damage to your liver or bile ducts.

 

Prothrombin Time (PT): This liver-produced protein measures how quickly your blood can clot. A higher PT level could indicate a liver disease or deficiency of vitamin K.

 

In conclusion, liver function tests are a valuable set of tools that help evaluate the functioning of the liver to determine if the hepatic tissues are healthy or afflicted by any disease.

 

Sources:
https://my.clevelandclinic.org/health/diagnostics/17662-liver-function-tests
https://www.mayoclinic.org/tests-procedures/liver-function-tests/about/pac-20394595#:~:text=Liver%20function%20tests%20check%20the,Alanine%20transaminase%20%28ALT%29