The best thing for your grandson to do is discuss his high blood sugar with an endocrinologist (doctor who specializes in diabetes.) He should be careful with what he eats. If he does'nt have a home blood glucose monitor already he should get one. He also should be taught how to use the monitor himself. Try checking glucose levels at different times on different days. Make sure he is taking insulin injections at the same time every day. It is very important that he get his blood sugar under control as this is the best way to avoid future complications.