Do you mean gamma glutamyltansferase?
If so, its one of the enzymes measured when undergoing a "Liver Function Test."
I'm not sure what units you are using, (?i.u/L) but if your levels are raised, it does need some investigating, although if the other levels are stable, your quack (sorry, Doctor), should be able to rule out most serious causes in his consulting room, and by sending you for more blood tests.
Isolated raised GGT can be a sign of prolonged excess alcohol intake, but this isn't always the case.
Do you drink, and if so how many units per week?
See
http://gpnotebook.com/simplepage.cfm...28073629828550