D-Dimer Test
Reviewed
Also called: fragment D-dimer, fibrin degradation fragment
A D-dimer test measures a protein fragment that appears in your blood when a blood clot forms and dissolves. It is used to help rule out clotting disorders such as deep vein thrombosis (DVT), pulmonary embolism (PE), or disseminated intravascular coagulation (DIC).
Specimen: blood
Urgent safety information
If you have symptoms of pulmonary embolism (PE) such as trouble breathing, chest pain, or rapid heartbeat, seek immediate medical attention.
Why this test may be ordered
- To evaluate if you may have a blood clot when you have symptoms of DVT or PE.
- To monitor treatment effectiveness for clotting disorders such as DIC.
Preparation and collection
No special preparations needed.
blood draw from arm vein
There is very little risk to having a blood test. You may have slight pain or bruising at the spot where the needle was put in, but most symptoms go away quickly.
Understanding results
Your D-dimer test result is given as a level of D-dimer in your blood. Your healthcare professional will interpret your result along with your symptoms, medical history, and other test results.
- Low or normal D-dimer level: You probably do not have a clotting disorder. Limitation: If you are taking blood thinner medicines, you may get a false negative result (the test shows no clotting problem when one actually exists). Next step: Your provider will consider your symptoms and medical history. If you have symptoms, further testing may be needed.
- Higher than normal D-dimer level: May indicate a clotting disorder such as deep vein thrombosis (DVT), pulmonary embolism (PE), disseminated intravascular coagulation (DIC), or stroke. This result alone is not diagnostic. Limitation: High D-dimer levels are not always caused by clotting disorders; they can also occur due to pregnancy, heart disease, rheumatoid arthritis, recent surgery, being older, or being immobilized. Next step: Your provider will likely order more tests (such as Doppler ultrasound, CT angiography, or V/Q scan) to locate the clot or determine the type of clotting disorder.
- False negative result possible if you are taking blood thinner medicines.
- High D-dimer levels can be caused by pregnancy, heart disease, rheumatoid arthritis, recent surgery, being older, or being immobilized.
What to do next
If your results show higher than normal D-dimer levels, your provider will likely order additional imaging tests such as a Doppler ultrasound, CT angiography, or ventilation-perfusion (V/Q) scan to determine where the blood clot is located or what type of clotting disorder you have.
- What are the common symptoms of a blood clot?
- Could any of my current medications affect my D-dimer test result?
- What other tests might I need if my D-dimer level is high?