<s>[INST] I am hypothyroid.. My recent blood test also showed a gamma GT rating of 74. I do not drink... What could be causing this?  I do have some pain under my right rib cage which flares up now and again. Had an ultrasound of my liver which came back fine. [/INST] Hi,Thanks for asking.Based on your query, my opinion is as follows.1. GGT is mildly elevated. 2. Ultrasound will detect only major abnormality.3. Biopsy of liver is necessary to rule out any hepatitis. Certain hepatotoxic medications can also raise GGT. Get a liver biopsy. With history of pain in right cage, a biopsy is necessary. Hope it helps.Any further queries, happy to help again. </s>