Skip to content

    Deep Vein Thrombosis Health Center

    Font Size
    A
    A
    A

    D-Dimer Test

    A d-dimer test is a blood test that measures a substance that is released when a blood clot breaks up. Doctors order the d-dimer test, along with other lab tests and imaging scans, to help check for blood-clotting problems. A d-dimer test can also be used to check how well a treatment is working.

    Why It Is Done

    Doctors use the d-dimer test when a person might have a dangerous blood-clotting problem. These problems include:

    How To Prepare

    No special preparation is required before having this test.

    How It Is Done

    The health professional drawing 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

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

    WebMD Medical Reference from Healthwise

    Last Updated: March 12, 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.

    Today on WebMD

    TAG dvt blood clot
    Symptoms, causes, risk factors, and more.
    businesswoman in airport
    Tips to prevent another clot.
     
    blood thinners
    Tips for DVT.
    Blood clots in artery
    Causes and treatments.
     
    Simple Steps to Lower Cholesterol
    Slideshow
    Having Surgery Tips To Reduce DVT Risk And More
    Slideshow
     
    New DVT Therapies On The Horizon
    Video
    Atrial Fibrillation Guide
    Slideshow
     

    WebMD Special Sections