D-dimer

D-dimer (or D dimer) is a <a href="/facts/Dimer_(chemistry)/mU64PnEq">dimer</a> that is a <a href="/facts/Fibrin_degradation_product/czslkV6E">fibrin degradation product</a> (FDP), a small protein fragment present in the blood after a <a href="/facts/Thrombus/vH6FDIQG">blood clot</a> is degraded by <a href="/facts/Fibrinolysis/moYzJ5Gx">fibrinolysis</a>. It is so named because it contains two D fragments of the <a href="/facts/Fibrin/BFar47y5">fibrin</a> protein joined by a <a href="/facts/Cross-link/zeQ9hEAA">cross-link</a>, hence forming a <a href="/facts/Protein_dimer/c8LwFJPG">protein dimer</a>.
D-dimer concentration may be determined by a <a href="/facts/Blood_test/zevsf3rC">blood test</a> to help diagnose <a href="/facts/Thrombosis/8Y3wh2UX">thrombosis</a>. Since its introduction in the 1990s, it has become an important test performed in people with suspected thrombotic disorders, such as <a href="/facts/Venous_thromboembolism/oQAalgo3">venous thromboembolism</a>. While a negative result practically rules out thrombosis, a positive result can indicate thrombosis but does not exclude other potential causes. Its main use, therefore, is to exclude <a href="/facts/Thromboembolism/8Y3wh2UX">thromboembolic</a> disease where the probability is low.
D-dimer levels are used as a predictive <a href="/facts/Biomarker/nk2LgXtq">biomarker</a> for the blood disorder <a href="/facts/Disseminated_intravascular_coagulation/CuWaSKQW">disseminated intravascular coagulation</a> and in the coagulation disorders associated with <a href="/facts/Coronavirus_disease_2019/YsUgvsaX">COVID-19 infection</a>. A four-fold increase in the protein is an indicator of poor prognosis in people hospitalized with <a href="/facts/COVID-19/YsUgvsaX">COVID-19</a>.

D-dimer open-in-new

D-dimer