Why my sgpt 90 is high bcoz my screening hepatitis a & b is negative?

Hep C: Hepatitis c can also cause elevated liver enzymes, in addition to hepatitis a + b. There are other blood test that can help diagnose whether there is a liver or a gallbladder problem as well as imaging studies such as an ultrasound to take a look at the size of the liver. Medications, hepatitis, alcohol and even obesity can cause liver problems.