Fasting Required: Yes - 8 Hours Specimen: Blood Results: 1-2 Business Days Description: GGT is an enzyme found in many organs such as the kidney, spleen, and pancreas. However, the main source of GGT is the liver. GGT is used to help detect liver disease and bile duct obstructions. Elevated GGT levels may be caused by liver disease, congestive heart failure, alcohol consumption and/or other conditions. While increased levels may indicate that the liver is being damaged, it does not specifically point to what may be causing the injury. Methodology Spectrophotometry (SP) Clinical Significance Elevated GGT is found in all forms of liver disease. Measurement of GGT is used in the diagnosis and treatment of alcoholic cirrhosis, as well as primary and secondary liver tumors. It is more sensitive than alkaline phosphatase, the transaminases, and leucine aminopeptidase in detecting obstructive jaundice, cholangitis, and cholecystitis. Normal levels of GGT are seen in skeletal diseases; thus, GGT in serum can be used to ascertain whether a disease, suggested by elevated alkaline phosphatase, is skeletal or hepatobiliary.