Diabetes incidence is growing very rapidly especially in Westernized countries where poor diet, sedentary lifestyle and obesity is increasing. Probably 1/2 of diabetics are yet to be diagnosed. The following will help you to know if you have diabetes or worse yet are developing it through what is called insulin resistance syndrome.
Fasting blood sugar of 126 mg% or higher; confirmed at a second test.
Or if a 2 hour glucose tolerance test is done and your 2 hour glucose is greater than 200. This is a test to see how your body metabolizes 75 grams of sugar. It should metabolize it quickly and not stay in the blood stream (high blood sugar).
You may casually get your blood sugar tested at a fair and not be fasting. Dont worry. Your blood sugar should be lower than 120 at any time following meals. If its higher then you may have insulin resistance (which may develop into diabetes) or have diabetes. Please seek medical advice if its elevated.