Liver function tests (LFTs), also known as liver panel or
hepatic function tests, are a group of blood tests that provide information
about the health and functioning of the liver. The liver is a vital organ
responsible for numerous functions in the body, including processing nutrients,
detoxifying harmful substances, producing important proteins, and aiding in
digestion. LFTs help doctors assess how well the liver is working and identify
any potential liver-related issues or diseases.
Here are some common liver function tests and what they
measure:
Alanine Aminotransferase (ALT): ALT is an enzyme found
primarily in the liver. Elevated ALT levels can indicate liver inflammation or
damage, often associated with conditions such as hepatitis (viral, alcoholic,
or autoimmune), fatty liver disease, and drug-induced liver injury.
Aspartate Aminotransferase (AST): Like ALT, AST is an enzyme
found in the liver, but it's also present in other organs like the heart and
muscles. Elevated AST levels can indicate liver damage, but they are less
specific to the liver than ALT. High AST levels may be seen in conditions such
as hepatitis, cirrhosis, and certain muscle disorders.
Alkaline Phosphatase (ALP): ALP is an enzyme found in
various tissues, including the liver, bile ducts, and bones. Elevated ALP
levels can indicate liver or bile duct obstruction, bone disorders, or other
conditions affecting bone growth.
Gamma-Glutamyl Transferase (GGT): GGT is an enzyme found in
the liver and other organs, including the pancreas and kidneys. Elevated GGT
levels can indicate liver disease, alcohol abuse, or certain medications
affecting the liver.
Bilirubin: Bilirubin is a waste product formed when red
blood cells break down. Elevated bilirubin levels can result from liver
disease, hemolysis (excessive breakdown of red blood cells), or bile flow obstruction.
High bilirubin levels can cause jaundice, a yellowing of the skin and eyes.
Albumin: Albumin is a protein produced by the liver that
helps maintain blood volume and transport substances. Low albumin levels can
indicate liver disease, malnutrition, or kidney problems.
Prothrombin Time (PT) and International Normalized Ratio
(INR): These tests assess the blood's ability to clot. The liver produces
clotting factors, so abnormal PT and INR values can indicate liver dysfunction.
Total Protein: This test measures the total amount of
proteins in the blood, including albumin and globulins. Abnormal total protein
levels can indicate liver disease or other underlying health issues.
Liver function tests are often performed together to get a
comprehensive view of liver health. It's important to note that abnormal test
results do not provide a specific diagnosis on their own. They are usually used
in conjunction with a patient's medical history, physical examination, and
possibly other diagnostic tests to determine the cause of the abnormalities and
guide further treatment or investigation. If you have concerns about your liver
health or have been advised to take liver function tests, it's best to consult
a medical professional for proper interpretation and guidance.