BACK TOTOP Browse A-ZSearchBrowse A-ZABCDEFGHIJKLMNOPQRSTUVWXYZ0-9 E-mail FormEmail ResultsName:Email address:Recipients Name:Recipients address:Message: Print-FriendlyBookmarksbookmarks-menuGamma-glutamyl transferase (GGT) blood testGamma-GT; GGTP; GGT; Gamma-glutamyl transpeptidaseThe gamma-glutamyl transferase (GGT) blood test measures the level of the enzyme GGT in the blood.EnzymeEnzymes are complex proteins that cause a specific chemical change in all parts of the body. For example, they can help break down the foods we eat ...Read Article Now Book Mark Article How the Test is Performed A blood sample is needed.Blood sampleVenipuncture is the collection of blood from a vein. It is most often done for laboratory testing.Read Article Now Book Mark Article How to Prepare for the Test The health care provider may tell you to stop taking medicines that can affect the test.Drugs that can increase GGT level include:Acetaminophen Alcohol Carbamazepine Phenytoin PhenobarbitalDrugs that can decrease GGT level include:Birth control pills Clofibrate How the Test will Feel When the needle is inserted to draw blood, some people feel moderate pain. Others feel only a prick or stinging. Afterward, there may be some throbbing or a slight bruise. This soon goes away. Why the Test is Performed GGT is an enzyme found in high levels in the liver, kidney, pancreas, heart, and brain. It is also found in lesser amount in other tissues. An enzyme is a protein that causes a specific chemical change in the body.This test is used to detect diseases of the liver or bile ducts. It is also done with other tests (such as the ALT, AST, ALP, and bilirubin tests) to tell the difference between liver or bile duct disorders and bone disease.BileBile is a fluid that is made and released by the liver and stored in the gallbladder. Bile helps with digestion. It breaks down fats into fatty acid...Read Article Now Book Mark Article ALTThe alanine transaminase (ALT) blood test measures the level of the enzyme ALT in the blood.Read Article Now Book Mark Article ASTThe aspartate aminotransferase (AST) blood test measures the level of the enzyme AST in the blood.Read Article Now Book Mark Article ALPAlkaline phosphatase (ALP) is a protein found in all body tissues. Tissues with higher amounts of ALP include the liver, bile ducts, and bone. A blo...Read Article Now Book Mark Article BilirubinThe bilirubin blood test measures the level of bilirubin in the blood. Bilirubin is a yellowish pigment found in bile, a fluid made by the liver. Bi...Read Article Now Book Mark Article It may also be done to screen for, or monitor, alcohol use. Normal Results The normal range for adults is 5 to 40 U/L.Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or may test different specimens. Talk to your provider about the meaning of your specific test results. What Abnormal Results Mean An increased GGT level may be due to any of the following:Alcohol use Diabetes Flow of bile from the liver is blocked (cholestasis) CholestasisCholestasis is any condition in which the flow of bile from the liver is slowed or blocked.Read Article Now Book Mark Article Heart failure Heart failureHeart failure is a condition in which the heart is no longer able to pump oxygen-rich blood to the rest of the body efficiently. This causes symptom...Read Article Now Book Mark Article Lack of blood flow to the liver Liver tissue death Liver cancer or tumor Lung disease Pancreas disease Scarring of the liver (cirrhosis) CirrhosisCirrhosis is scarring of the liver and poor liver function. It is the last stage of chronic liver disease.Read Article Now Book Mark Article Swollen and inflamed liver (hepatitis) HepatitisHepatitis is swelling and inflammation of the liver.Read Article Now Book Mark Article Use of drugs that are toxic to the liver Risks There is little risk involved with having your blood taken. Veins and arteries vary in size from one person to another and from one side of the body to the other. Taking blood from some people may be more difficult than from others.Other risks associated with having blood drawn are slight but may include:Fainting or feeling lightheaded Multiple punctures to locate veins Hematoma (blood collecting under the skin) Excessive bleeding Infection (a slight risk any time the skin is broken)Open ReferencesReferencesChernecky CC, Berger BJ. Gamma-glutamyltranspeptidase (GGTP, gamma-glutamyltransferase) - blood. In: Chernecky CC, Berger BJ, eds. Laboratory Tests and Diagnostic Procedures. 6th ed. St Louis, MO: Elsevier Saunders; 2013:559-560.Daniels L, Khalili M, Goldstein E, Bluth MH, Bowne WB, Pincus MR. Evaluation of liver function. In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods. 24th ed. Philadelphia, PA: Elsevier; 2022:chap 22.Pratt DS. Liver chemistry and function tests. In: Feldman M, Friedman LS, Brandt LJ, eds. Sleisenger and Fordtran's Gastrointestinal and Liver Disease: Pathophysiology/Diagnosis/Management. 11th ed. Philadelphia, PA: Elsevier; 2021:chap 73.AllVideoImagesTog Tests for Gamma-glutamyl transferase (GGT) blood test Gamma-glutamyl transferase (GGT) blood testLeucine aminopeptidase blood testRelated Information Enzyme(Special Topic)Bile(Special Topic)Osteomyelitis(Condition)Amino acids(Special Topic)Metabolism(Special Topic)ALP - blood test(Medical Test)Heart failure(Condition)Cholestasis(Condition)Cirrhosis(Condition)Hepatic(Special Topic)Heart failure(In-Depth)Cirrhosis(In-Depth)Hepatitis(In-Depth) Review Date: 1/17/2021 Reviewed By: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team. 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