Why would I need this test?

Hemoglobin A1c is a blood test that shows the average level of glucose in your blood during the last three months. Monitoring your blood glucose every day is important, but this test is the most accurate way of knowing how well your treatment program is working.

Blood glucose is high when diabetes is poorly controlled. Glucose binds chemically (or glycates) with hemoglobin molecules in your red blood cells. The lower the percentage of glycated hemoglobin (hemoglobin A1c) in your blood, the better you've controlled your diabetes.

If you have diabetes, your A1c should be tested at least twice a year to check the effectiveness of your diabetes control program. If your results are high or your treatment plan has changed, you should be tested every three months until your blood glucose level stabilizes.

How can I prepare for this test?

You don't need to adjust your diet or medications prior to this test.

How is this test performed?

This test is done by collecting and analyzing a small sample of blood, usually from a vein in your arm. Initially, the puncture site is cleaned with an antiseptic, and an elastic band or blood pressure cuff is placed around the upper arm to restrict blood flow through the vein. This causes the vein below the elastic band to fill with blood. A nurse, medical technician or phlebotomist inserts a needle into the vein and collects a blood sample. You may feel slight discomfort from the needle puncture. During the procedure, the elastic band is removed to restore circulation. Once the blood sample has been collected, the needle is removed and the puncture site is covered to stop any bleeding. The blood is sent to a lab for analysis.

How long does the procedure take?

This blood test takes less than three minutes.

What happens if an abnormality is found?

If your results are higher than the recommended level, your treatment might need adjustment. Review your treatment plan and health habits with your health care team. Your health care provider will most likely want you to follow a specific diet, exercise regularly, take prescribed medications and frequently monitor your blood glucose level.

Are there any risks associated with this test?

There are no risks associated with this test.

What is a desirable reading?

A hemoglobin A1c less than 7 percent is your goal (5 percent is the average for people who do not have diabetes). At a level less than 7 percent, you help reduce your risk for serious complications from diabetes, such as blindness, kidney failure and nerve damage.