A D-dimer test looks for D-dimer in blood. D-dimer is a protein fragment (small piece) that’s made when a blood clot dissolves in your body. A D-dimer test is most often used to find out whether you have a blood clotting disorder. You may need this test if you have symptoms of a blood clotting disorder, such as deep vein thrombosis (DVT) or a pulmonary embolism (PE).
No specific precaution required for this test.