How Liver Function Tests Can Help Diagnose Medical Conditions?

The liver is situated in the upper right-hand portion of the abdominal cavity, positioned below the diaphragm and above the stomach, right kidney, and intestines. The liver serves as a vital organ in the metabolic processes of the body. These functions include:

1. Breaking down or converting glucose and toxic ammonia.
2. Regulating energy metabolism by converting glycogen into glucose and storing excess glucose as glycogen.
3. Detoxifying harmful substances in the body and eliminating them from the bloodstream.

Liver function tests (LFTs) are carried out to assess how well your liver is functioning. These tests are used to screen, detect, evaluate, and monitor acute and chronic liver inflammation (hepatitis), infections, liver diseases, and/or damages, including those caused by medications. LFTs are used to assess the levels of enzymes, proteins, and substances that are either produced or eliminated by the liver. This enables healthcare providers to understand any decline in its function or the presence of any liver damage.

Who is recommended to undergo liver function tests?

Liver function tests play a crucial role in evaluating the presence of any liver dysfunction, disease, or injury. This comprehensive assessment aids in determining the overall well-being of the liver and its different components. LFTs may be ordered:

• If you have a medical history of hepatic disorders or potential exposure to hepatitis viruses.
• If you have consumed excessive alcohol and it has resulted in damage to your liver tissue.
• If you have a family history of liver diseases.
• If you have consumed any medication or drugs that could potentially impact your liver.

Typically, a diagnosis is not made based on a single set of liver tests. It is often necessary to conduct several liver function tests to help determine the underlying cause of the liver disorder. If abnormal results are detected in a liver function test panel, a repeat analysis may be needed to assess whether the elevation or decrease persists. Additionally, it may indicate the requirement for additional testing to identify the cause of the liver dysfunction.

What are the symptoms of liver disease?

Liver function tests are commonly ordered when an individual exhibits signs and symptoms of liver disease or an infection such as hepatitis. Some of these symptoms include:

• Weakness
• Loss of appetite
• Nausea
• Vomiting
• Bloated stomach
• Stomach pain
• Jaundice
• Dark urine
• Light coloured stool
• Pruritus (itching)

What does liver function test measure?

A liver panel includes the following tests:

Aspartate aminotransferase (AST): AST is an enzyme that aids in the metabolic process of amino acids. High AST blood levels can be a sign of liver damage or disease.

Alanine aminotransferase (ALT): ALT is another enzyme that helps break down proteins and is found primarily in the liver. High blood levels of ALT may indicate liver damage.

Alkaline phosphatase (ALP): ALP is an enzyme found in liver, bile ducts, and bone. You may have high levels of ALP if you have liver damage or disease, a blocked bile duct, or bone disease.

Bilirubin: Bilirubin Blood Test is produced during normal break down of red blood cells. Higher than normal levels of bilirubin (jaundice) may indicate liver damage or disease.

Albuminand total protein: Albumin is one of the many proteins made in the liver. Your body uses this protein to fight infections and to perform other functions. Decreased albumin and total protein levels may be indicative of liver damage or disease.

Gamma-glutamyl transferase (GGT): GGT is an enzyme found mainly in the liver cells. High levels of GGT enzyme may indicate liver or bile duct damage.

L-lactate dehydrogenase (LD): LD is an enzyme in the liver. Elevated LD levels may suggest liver damage, although they can also be elevated in various other medical conditions.

Prothrombin time (PT): PT is the time taken by your blood to clot. Elevated PT levels can be indicative of liver damage, but they may also be a result of taking certain blood-thinning drugs.

Interpretation of the liver function test results

In this test, a blood sample is taken to measure different liver enzymes such as alanine aminotransferase, alkaline phosphatase, bilirubin, etc. The normal liver function test values are as follows:

Deviation from normal levels indicates the following:

1. A higher-than-normal ALT test result can be a sign of liver damage. Very high levels are most often caused by viral hepatitis, ischemic hepatitis, or injury from drugs or other chemicals.
2. A high result of AST may be because of a problem with your liver or muscles. Elevated AST without elevated ALT may indicate muscle disease. If ALT, bilirubin, and ALP are also elevated, it may indicate liver damage.
3. Elevated levels of ALP may be a sign of liver inflammation, blockage of the bile ducts, or bone disease.
4. A low albumin test result may indicate that the liver is not functioning properly. This occurs in diseases such as malnutrition, liver cirrhosis, and cancer.
5. A high bilirubin test result may indicate impaired liver function. Elevated bilirubin levels with elevated ALT or AST levels may indicate cirrhosis or hepatitis.
6. A high GGT test result may indicate damage to the liver or bile ducts.
7. Elevated levels of LD or PT may indicate liver damage.

Liver function tests are blood tests that are used to evaluate the well-being of your liver. Changes in the levels of certain proteins or enzymes can serve as indicators about potential problems such as liver cancer or hepatitis. These tests can also be useful in identifying whether particular medications are causing any damage to your liver or in keeping track of the progression of liver disease. Following a liver function test, your healthcare provider will guide you in understanding the results, and if there is a suspicion of liver disease, further tests such as imaging or a liver biopsy may be required.