Diabetics aim for a blood sugar reading of under 120. Typically 80-120 is a normal blood sugar range for people. When your blood sugar is controlled and maintained within these normal ranges, then a diabetic has a far better chance of delaying, if not preventing, complications from this disease.
The only way for diabetics to check their blood sugar range is to prick their fingertips 4-6 times per day (or as often as necessary) to put a drop of blood on a blood sugar meter. Depending on what that number is, and calculating their food intake, a type 1 diabetic will take an insulin injection to regulate their blood sugar to be within this range.
What is Type 1 Diabetes? You can read the Wikipedia article by clicking here. Type 1 diabetes is usually diagnosed in children and young adults before the age of 25 and is currently an incurable, lifelong disease. It is a genetic thing and it is not caused by eating too much sugar. Type 1 diabetes is not the same thing as Type 2 diabetes.