• Glycosylated Hemoglobin Test

    (HbA1c; GHb; Glycohemoglobin; Diabetic Control Index)


    A glycosylated hemoglobin test (HbA1c) is a blood test that measures the percentage of hemoglobin (a protein found in blood red cells) that has attached to glucose. The higher your blood sugar is, the more that glucose gets attached to your hemoglobin.
    glucose and RBC
    Copyright © Nucleus Medical Media, Inc.

    Reasons for Test

    HbA1c shows how high your blood sugar levels have been during the past 3 months.
    • This can help your doctor determine how well you are controlling your diabetes.
    • Your doctor may also use HbA1c to test you for diabetes.
    • It may also be used to screen for diabetes in high risk people, including:
      • Adults of any age who are overweight or obese (BMI ≥ 25 kg/m²)
      • People who have one or more additional risk factors for diabetes, such as first-degree relative with type 1 diabetes, polycystic ovarian syndrome, or high risk ethnic background

    Possible Complications

    There are no major complications associated with this test.

    What to Expect

    Description of Test

    You will be asked to sit. An area inside your elbow will be cleaned with an antiseptic wipe. A large band will be tied around your arm. The needle will then be inserted into a vein. A tube will collect the blood from the needle. The band on your arm will be removed. After all the blood is collected, the needle will be removed. Some gauze will be placed over the site to help stop bleeding. You may also be given a bandage to place over the site. The process takes about 5-10 minutes.

    After Test

    Apply pressure to the site until bleeding stops.

    How Long Will It Take?

    Less than 5 minutes

    Will It Hurt?

    It may hurt slightly when the needle is inserted.


    If your HbA1c levels are high and you have never been diagnosed with type diabetes talk to your doctor about what to do next
    Talk to your doctor about what goal is right for you. If your HbA1c levels are high, you may need a change in treatment, such as:
    • Changing your medications
    • Increasing your level of physical activity
    • Modifying your diet
    Talk with your doctor about when you should be tested again.

    Call Your Doctor

    After the test, call your doctor if any of the following occurs:
    • Redness
    • Swelling
    • Persistent bleeding or discharge
    • Pain
    If you think you have an emergency, call for emergency medical services right away.


    American Diabetes Association http://www.diabetes.org

    National Diabetes Education Program http://ndep.nih.gov


    Canadian Diabetes Association http://www.diabetes.ca

    Health Canada http://www.hc-sc.gc.ca


    American Diabetes Association. Standards of medical care in diabetes—2014. Diabetes Care. 2014 Jan;37 Suppl 1:S14-80.

    Diabetes mellitus type 1. Available at: http://www.dynamed.com/topics/dmp~AN~T116244/Diabetes-mellitus-type-1. Updated May 31, 2017. Accessed August 29, 2017.

    Glycemic control monitoring. Available at: http://www.dynamed.com/topics/dmp~AN~T114088. Updated May 31, 2017. Accessed August 29, 2017.

    HbA1c measurement. Available at: http://www.dynamed.com/topics/dmp~AN~T900926/HbA1c-measurement. Updated February 13, 2017. Accessed August 29, 2017.

    Revision Information

  • LiveWell personal health survey

    How healthy are you really? Find out – free.Learn more

    It's time to stop guessing. If you want to make some changes but just aren't sure how, the free personal health survey from LiveWell is a great place to start.

  • HeartSHAPE Spotlight

    At risk for a heart attack? Learn more

    Fight heart disease and prevent heart attacks. HeartSHAPE® is a painless, non-invasive test that checks pictures of your heart for early-stage coronary disease.

  • Calories and Energy Needs

    Calorie NeedsLearn more

    How many calories do you need to eat each day to maintain your weight and fuel your physical activity? Enter a few of your stats into this calculator to find out.

  • Ideal Body Weight

    Ideal Body WeightLearn more

    Using body mass index as a reference, this calculator determines your ideal body weight range. All you need to do is enter your height.

  • Body Mass Index

    Body Mass IndexLearn more

    This tool considers your height and weight to assess your weight status.

  • Can we help answer your questions?

    Wellmont Nurse Connection is your resource for valuable health information any time, 24 hours a day, seven days a week. Speak to a Nurse any time, day or night, at (423) 723-6877 or toll-free at 1-877-230-NURSE.