A1C test and diabetes, what does it mean?

My Doctor told me my A1C is elevated, what does that mean?

The hemoglobin A1C test (also known as HbA1C or just A1C) measures your average blood glucose control for the past 2-3 months.  When you check your blood glucose with your meter at home or in the doctor’s office you get a reading of what your blood glucose level is right now.  The A1C test tells you what your average control has been over the last 2-3 months.  This result lets you know, on average, how well your diabetes treatment plan has been working over the past 3 months. 

Hemoglobin is a protein found in your red blood cells.  Hemoglobin carries oxygen from your lungs to all of the cells in your body.  Hemoglobin will also bind with sugar.  Normally, about 5% of all hemoglobin is connected to sugar.  When someone is hyperglycemic (has too much sugar in their blood) this percentage increases sometimes up to 25%.  The A1C test will measure this percent. 

The A1C test gives a 3 month average because the life of a red blood cell is about 3 months.  Patients with diabetes should check their A1C about every 3 months.  If their sugars are fairly stable, than twice a year may be adequate.  Your doctor will help you decide how often you should check yours.   Normal A1C is 5% and the American Diabetes Association recommends keeping A1C less than 7%.   The numbers may be a little different for teens and children.
The A1C is a great measure of how your diabetic regimen is working for you, however, it does not replace the need for daily self-testing.