The hemoglobin A1c blood test can show your blood sugar levels over time. It's also called the glycated hemoglobin test. This test measures your average blood sugar level over the past 2 to 3 months. A higher A1c result means your blood sugar has been high. This means that you may have a higher risk of problems from diabetes.
The A1c is a blood test done by your doctor. Sometimes the A1c test is used as a screening tool. This means it's used to see if a person has prediabetes or diabetes. More often it is used to see how well you are managing your blood sugar. You will likely have an A1c test every 3 to 6 months.