Diabetes. Fasting glucose levels as well as hemoglobin a1c level will tell you if you have diabetes. These can be done by your primary care doctor.
Blood tests. There are blood tests for blood sugar. Your doctor will interpret the result to tell you whether or not you have type 2 diabetes. He may also choose to do a hgba1c level to make the decision. The blood tests are usually done fasting and two hours after a meal.