The diagnosis of thrombotic disorders has received a great deal of attention in the past decade and recently its importance in COVID-19 screening and monitoring has opened a whole new window. The morbidity and mortality of this potential complication are major concerns. Despite the alarming mortality numbers, the diagnosis of these disorders remains challenging. A novel approach to the diagnosis has received a great deal of scrutiny recently; is the use of a D-dimer assay. D-dimer was originally described in the 1970s and found its diagnostic application in the 1990s. It is so named because it contains two D fragments of the fibrin protein joined by a cross-link. D-dimer is a marker of fibrinolysis and is a fibrin degradation product (FDP), a small protein fragment present in the blood after a blood clot is degraded by fibrinolysis. Circulating levels can be detected as early as one hour after thrombus formation. A positive D-dimer result may indicate the presence of an abnormally high level of fibrin degradation products (FDP’s). It indicates that there may be significant blood clot (thrombus) formation and breakdown in the body.