D-Dimer Test
Reviewed
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).
Preparation and collection
No special preparations needed.
Understanding this test
Use the reference interval and units printed by the laboratory that performed the test. A result outside that interval is not a diagnosis by itself, and a result inside it does not rule out every condition. Your symptoms, history, medicines, timing, and related tests can change what the result means.
- 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.