Liver function tests (LFTs) are critical diagnostic tools used to evaluate the health and performance of your liver. By measuring specific enzymes, proteins, and other substances, these tests provide valuable insight into how well your liver is functioning. Here, we explore nine essential marker s in a liver function test and what they reveal about your liver’s condition.

1. Total Bilirubin

Bilirubin is a yellow pigment produced during the breakdown of red blood cells. It is processed by the liver and then excreted from the body through bile. When your liver is not functioning properly, bilirubin may accumulate in the blood, leading to elevated levels. This can cause jaundice, a condition characterized by yellowing of the skin and eyes.

• What does it indicate? Elevated bilirubin levels can point to liver dysfunction, bile duct obstruction, or diseases like hemolytic anemia. It is also a common marker for conditions such as hepatitis, cirrhosis, or gallstones.
• Normal range: 0.1 to 1.2 milligrams per deciliter (mg/dL).

2. Total Protein

The total protein test measures the amount of two primary proteins in the blood: albumin and globulin. These proteins perform essential roles, including immune function and nutrient transport. Total protein levels give an overall picture of liver health and protein production.

• What does it indicate? Low total protein may suggest liver disease, malnutrition, or kidney disorders. Elevated levels could indicate chronic inflammation or infections.
• Normal range: 6.0 to 8.3 grams per deciliter (g/dL).

3. Albumin

Albumin is the most abundant protein produced by the liver. It plays a key role in maintaining fluid balance within the bloodstream and transporting substances like hormones, drugs, and enzymes. Low albumin levels are often the result of liver disease, as the liver struggles to produce enough of this protein.

• What does it indicate? A low albumin level can be a sign of chronic liver disease, such as cirrhosis or hepatitis, as well as kidney disease or malnutrition. Severe liver damage may severely affect albumin production.
• Normal range: 3.5 to 5.0 g/dL.

4. Globulin

Globulin proteins support immune system functions, assist in blood clotting, and help fight infections. Globulin levels are important in diagnosing liver disease because the liver is responsible for producing many of these proteins.

• What does it indicate? Abnormal globulin levels may suggest liver disease, chronic inflammation, or autoimmune disorders like lupus. A low albumin-to-globulin ratio is often used to indicate liver dysfunction.
• Normal range: 2.0 to 3.5 g/dL.

5. Alkaline Phosphatase (ALP)

ALP is an enzyme found in many tissues, including the liver, bones, and bile ducts. It plays a crucial role in breaking down proteins in the body. In liver function tests, elevated ALP levels can be a sign of liver damage or bile duct obstruction.

• What does it indicate? High ALP levels are associated with conditions such as cholestasis (impaired bile flow), liver tumors, or bone disorders like Paget’s disease. It can also point to liver inflammation caused by hepatitis or cirrhosis.
• Normal range: 44 to 147 international units per liter (IU/L).

6. Aspartate Aminotransferase (AST)

AST is an enzyme that helps break down amino acids and is found in high concentrations in the liver and heart. When liver cells are damaged or destroyed, AST is released into the bloodstream. However, because AST is also found in muscles and other tissues, it is not liver-specific.

• What does it indicate? Elevated AST levels could indicate liver damage due to hepatitis, fatty liver disease, or alcohol abuse. However, it may also signal muscle injury or heart conditions like a recent heart attack.
• Normal range: 10 to 40 IU/L.

7. Alanine Aminotransferase (ALT)

ALT is another enzyme primarily found in the liver, making it a more liver-specific marker than AST. ALT plays a role in converting stored energy in the liver into usable energy for the body. Like AST, ALT is released into the blood when the liver is damaged.

• What does it indicate? High ALT levels are often a sign of liver inflammation or injury, such as viral hepatitis, non-alcoholic fatty liver disease (NAFLD), or alcohol-induced liver damage. ALT is usually elevated earlier than AST, making it a valuable early marker.
• Normal range: 7 to 56 IU/L.

8. Gamma-Glutamyl Transferase (GGT)

GGT is an enzyme that assists in the transport of amino acids and the metabolism of drugs and toxins in the liver. GGT is particularly sensitive to changes in bile flow, making it an important marker for detecting bile duct problems.

• What does it indicate? Elevated GGT levels are commonly seen in people with liver disease, especially those who consume large amounts of alcohol. It is also a marker for bile duct obstruction, cholestasis, and pancreatitis. When combined with ALP results, GGT can help pinpoint the source of liver or bile duct issues.
• Normal range: 9 to 48 IU/L.

9. Fibrosis-4 (FIB-4)

The Fibrosis-4 (FIB-4) index is a non-invasive score that estimates the extent of liver fibrosis, or scarring, by using a formula that includes age, AST, ALT, and platelet count. This score is particularly useful for monitoring the progression of chronic liver diseases like hepatitis or cirrhosis.

• What does it indicate? A high FIB-4 score suggests significant liver scarring, which can occur in patients with chronic liver conditions like viral hepatitis or fatty liver disease. Monitoring FIB-4 over time helps determine the need for more intensive treatments or monitoring.
• Normal range: Calculated based on age and blood results; values above 3.25 suggest advanced fibrosis.

At Blessono Specialist Clinic, we provide detailed liver function testing to assess your liver health and detect potential issues early. Regular liver function tests are crucial, especially if you have risk factors such as a history of alcohol consumption, hepatitis, or obesity. Early detection can prevent severe liver disease and ensure better long-term health outcomes.