Liver Function Tests
Liver function tests
are laboratory blood tests meant to show details about the condition of the patient's liver. Tests may be associated with functionality, cellulary integrity, or biliary tract condition. In many cases, liver disease
is initially without symptoms (asymptomatic) or presents nothing more than mild symptoms. Even so, it is often important that the conditions be diagnosed in their early stages. Therefore, liver function tests may be helpful in early detection of liver disease.
Liver function tests primarily check for decreased or elevated liver enzymes. Some tests may include:
- Albumin is a protein made by the liver. It may be decreased in certain instances of chronic liver disease
, etc.), nephrotic syndrome, and poor nutrition. Having low albumin is a condition known as hypoalbuminemia.
Alanine transaminase (ALT)
is raised in acute liver damage (viral hepatitis
, acetaminophen/paracetamol overdose, etc.). When hepatocytes (liver cells) are damaged, this enzyme is leaked into the blood. It is also known as serum glutamic pyruvate transaminase (SGPT) or alanine aminotransferase (ALAT).
Aspartate transaminase (AST)
is raised in conditions of acute liver damage, however it is not liver-specific. AST to ALT ratio is at times used to differentiate the underlying cause of liver damage. It is also known as serum glutamic oxaloacetic transaminase (SGOT) or aspartate aminotransferase (ASAT).
Alkaline phosphatase (ALP)
- ALP plasma levels may be raised in infiltrative liver diseases
, intrahepatic cholestasis, or large bile duct obstruction. However, it is also elevated in growing children, and in Paget's disease patients amongst the elderly.
Direct bilirubin (DBIL)
- If total bilirubin is elevated then DBIL may assist in further detailing the issue. If the direct bilirubin is normal, then upstream bilirubin excretion is problematic (cirrhosis
, hemolysis, viral hepatitis
, etc). If however the direct bilirubin is elevated, then bilirubin conjugation is normal, but excretion is not happening properly (cancer
Gamma glutamyl transpeptidase (GGT)
- GGT may be raised in liver dysfunction, even where the condition is considered subclinical. In particular, it is raised with alcohol toxicity.
Total bilirubin (TBIL)
- Total bilirubin increase may be in one of three ways: prehepatic (increased production), hepatic (liver problems), or posthepatic (bile duct obstruction). Increased total bilirubin may lead to jaundice.
For more general information about elevated liver enzymes, return to the home page
. Otherwise, you can keep reading about specific aspects: symptoms
, or treatment options
Return to top