An elevated level of gamma-glutamyl transpeptidase enzymes indicates that there is liver damage, but the GGT test does not determine the cause. Some symptoms of high GGT include fatigue, decreased appetite, nausea, vomiting, and swelling or pain in the abdomen, says Lab Tests Online.
Generally, the higher the level of GGT, the more damage has been done to the liver. This could rule out bone disease as the cause if the level of alkaline phosphatase enzymes in the liver is also high, according to Lab Tests Online. Other symptoms of elevated GGT include light-colored stools, dark-colored urine, jaundice and itching.
An elevated level of GGT could be the result of liver diseases such as scarring, necrosis, tumors, ischemia or hepatitis. Other medical conditions that could cause it include pancreatitis, diabetes or heart failure. Lung disease and the blockage of bile from the liver are other potential causes. The use of drugs that are toxic to the liver or alcohol abuse may also increase GGT levels, according to MedlinePlus.
GGT enzymes are transport molecules that help move other molecules and enzymes throughout the body. They have a vital role in metabolizing medications and other toxins, explains Healthline. GGT is mostly present in the liver, but it is also in the pancreas, gallbladder, kidneys and spleen. Testing of this enzyme is often combined with other liver enzyme tests.