<P> D - dimer (or D dimer) is a fibrin degradation product (or FDP), a small protein fragment present in the blood after a blood clot is degraded by fibrinolysis . It is so named because it contains two D fragments of the fibrin protein joined by a cross-link . </P> <P> D - dimer concentration may be determined by a blood test to help diagnose thrombosis . Since its introduction in the 1990s, it has become an important test performed in patients with suspected thrombotic disorders . While a negative result practically rules out thrombosis, a positive result can indicate thrombosis but does not rule out other potential causes . Its main use, therefore, is to exclude thromboembolic disease where the probability is low . In addition, it is used in the diagnosis of the blood disorder disseminated intravascular coagulation . </P>

The d-dimer test detects degradation products from the breakdown of which clotting proteins