A person without diabetes will have an A1C test below 5.7%, a fasting blood glucose test less than 100 mg/dl, and a glucose tolerance test of 140 mg/dl or below. Learn more about diabetes test results.

The A1C (also called HbA1c) is a blood test that shows how blood sugar levels were controlled over the previous two to three months. It should be done by your doctor at least twice a year. Aim for a level below 6.5.

No, fasting is not required for an A1C because the test measures your average blood glucose levels over the past three months. 

At least 10 hours gives your body a chance to digest all food in your system to more readily determine what your true fasting blood sugar is. Carbs, proteins and fats all digest at a different rate and a larger meal will take longer to digest. A fasting blood sugar of 126 repeated twice is a diagnosis of diabetes.

No, do not drink coffee, even if it is black. You can only drink plain water so do not drink coffee, tea, or anything else before a fasting blood test, even if it is diet/unsweetened.

Illness can lead to an increase in blood sugar levels. The most important step to take during illness is to make sure that blood sugar levels are stable to prevent a small problem like a cold or the flu from causing greater problems. Learn more about diabetes and illness.