Hemoglobin A1c Test

What is the hemoglobin A1c test?

The hemoglobin A1c ("A-one-C") test is a blood test used in the care of people who have diabetes. The hemoglobin A1c percentage is a way of looking at your average blood sugar control over a period of 3 months.

Sugar absorbed from your digestive system circulates in the bloodstream. When the blood sugar is high, the sugar attaches to the hemoglobin protein in red blood cells, forming hemoglobin A1c.

Red blood cells live 90 to 120 days. This means that once sugar has combined with the hemoglobin in red blood cells, the hemoglobin A1c stays in the blood for 90 to 120 days. This means the amount of hemoglobin A1c in your blood reflects how often and how high your blood sugar has been over the past 3 months.

Why is this test done?

Hemoglobin A1c is an excellent way to check how well you are controlling your blood sugar over a 3-month period.

Hemoglobin A1c measurements are important because:

• They confirm your daily home blood sugar monitoring results.
• They help predict your risk of diabetic complications. The higher the hemoglobin A1c percentage, the greater the risk of developing diabetic eye, kidney, cardiovascular, and nervous system disease.

How do I prepare for this test?

No preparation is necessary. One of the advantages of this test is that you do not have to fast before you take it.

How is the test done?

A small amount of blood is taken from your arm with a needle. The blood is collected in tubes and sent to a lab.

Having this test will take just a few minutes of your time. There is no risk of getting AIDS, hepatitis, or any other blood-borne disease from this test.

How will I get the test result?

Ask your health care provider when and how you will get the result of your test.

What does the test result mean?

The hemoglobin A1c percentage rises as your average blood sugar level rises. For adult diabetics the results are usually judged as follows:

• less than 7%: excellent blood sugar control
• less than 8.0%: good control
• less than 9.0%: fair control
• 9.1% or higher: poor control.

What if my test result is not normal?

If you have not yet been diagnosed with diabetes and your test is not normal, you need to talk with your health care provider about whether you have diabetes.

If you have been diagnosed as diabetic and your test is not normal, your health care provider will talk to you about how to lower your blood sugar through diet, exercise, and/or medicine. Maintaining blood sugar levels and hemoglobin A1c levels in or near normal ranges will help you avoid the complications of diabetes.

If your test results are not normal, ask your health care provider:

• if you need additional tests
• what you can do to work toward a normal value
• when you need to be tested again.