The A1C test is a blood test that determines your average blood glucose level over the previous two to three months. Diabetes-related problems of the heart, blood vessels, kidneys, eyes, and feet can be caused by high A1C levels. Your doctor should advise you how often you should have your A1C tested each year. The test is typically done twice a year for those who meet their diabetes treatment goals. A1C levels of less than 7% are considered desirable. Learn more in our blog article, "Tips on Managing Your Diabetes with Oral Health and More."