High GGT levels indicates many problems including that a person has diabetes, heart failure, hepatitis, alcohol abuse, cholestasis, a liver tumor, live necrosis, liver ischemia, pancreas disease, lung disease, cirrhosis or has been using liver damaging drugs, according to the U.S. National Library of Medicine. GGT is known as gamma-glutamyl transferase and is a type of protein that is found in the liver cells and in the blood, says the University of Rochester's Medical Center.
There are drugs that can increase and decrease the levels of GGT found in the blood. Alcohol, phenobarbital and phenytoin all increase the GGT level while birth control pills and clofibrate decrease the GGT level according to the University of Rochester Medical Center. The normal range for the GGT level is 0 to 51 IU/L or international units per liter, notes the University of Rochester Medical Center.
The test is administered by drawing blood through a needle that must puncture the skin. Some people report feeling pain and a throbbing sensation after the needle has been inserted yet other people report a lack of pain. The test itself poses few risks and the most severe risks are infection and hematoma, both of which are rare, says the University of Rochester Medical Center.