D-Dimer: an analyte with increasing application in Covid-19 infection

D- Dimer levels from peripheral blood are increasingly used to assess various pathological conditions. Initially, an area for hematologists, now this analyte is evaluated more extensively from many specialties of medicine. Covid-19 infection has not only added a new dimension to D-Dimer level assessment in this disease but has also shed newer lights to the underlying pathophysiological mechanisms for its elevation in this disease.Innate variability in measuring D- Dimer levels, Impact of various techniques in measuring D- Dimer, nonavailability of uniform controls and standards, molecular heterogeneity of the product, how it is produced. Reasons for raised D- Dimer in covid-19 infection. D- Dimer in other pathological states. Articles with relevant key words from 1990 searched in PubMed were utilized for review.: D-Dimer has important application in diagnosis, prognosis, management, and understanding various conditions. Its level can rise with increased coagulability of blood, sepsis, cytokine storm, snake bite, etc. Renal function, age influences its reference ranges. Units of measurement, its expression varies in different reports needing international standardization. In Covid-19 infection its levels correlate with stage of the disease, pathology, and complications.