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    Glycohemoglobin (HbA1c, A1c)

    How To Prepare

    You do not need to stop eating before you have an A1c test. This test can be done any time during the day, even after a meal.

    How It Is Done

    The health professional taking a sample of your blood will:

    • Wrap an elastic band around your upper arm to stop the flow of blood. This makes the veins below the band larger so it is easier to put a needle into the vein.
    • Clean the needle site with alcohol.
    • Put the needle into the vein. More than one needle stick may be needed.
    • Attach a tube to the needle to fill it with blood.
    • Remove the band from your arm when enough blood is collected.
    • Put a gauze pad or cotton ball over the needle site as the needle is removed.
    • Put pressure on the site and then put on a bandage.

    How It Feels

    The blood sample is taken from a vein in your arm. An elastic band is wrapped around your upper arm. It may feel tight. You may feel nothing at all from the needle, or you may feel a quick sting or pinch.

    Risks

    Blood test

    There is very little chance of a problem from having blood sample taken from a vein.

    • You may get a small bruise at the site. You can lower the chance of bruising by keeping pressure on the site for several minutes.
    • In rare cases, the vein may become swollen after the blood sample is taken. This problem is called phlebitis. A warm compress can be used several times a day to treat this.
    • Ongoing bleeding can be a problem for people with bleeding disorders. Aspirin, warfarin (Coumadin), and other blood-thinning medicines can make bleeding more likely. If you have bleeding or clotting problems, or if you take blood-thinning medicine, tell your doctor before your blood sample is taken.

    Results

    A1c is a blood test that checks the amount of sugar (glucose) bound to hemoglobin camera.gif. The result is shown as a percentage. The result of your A1c test can also be used to estimate your average blood sugar level. This is called your estimated average glucose, or eAG. Your doctor will have your test results in a few days.

    WebMD Medical Reference from Healthwise

    Last Updated: August 06, 2014
    This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.

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