A normal glucose level when not fasting is between 70 to 99 milligrams per deciliter, states Virginia Mason Medical Center. A normal glucose level two hours after a meal is under 140 milligrams per deciliter. Glucose is also referred to as blood sugar.
When a person's glucose is too high, it can damage the eyes, kidneys, nerves and blood vessels, states WebMD. If a person's glucose remains high, but not at diabetic levels, he may have pre-diabetes. Doctors test the amount of glucose several times during the day, including when a person fasts for eight hours and two hours after he eats. Doctors can also test at random times, and if the glucose levels remain consistent, the person is healthy.