Fig. 1.

Virchow’s triad in the thrombogenesis in COVID-19. Virchow’s triad consists of abnormal vessel wall (endotheliitis, endothelial dysfunction with loss of glycocalyx, endothelial disruption), abnormal flow (due to hyper-viscosity, immune activation, high fibrinogen, impaired microcirculation due to hypoxia and turbulent flow due to microthrombi), and hypercoagulable state (inhibition of plasminogen system due to unopposed canonical renin-angiotensin pathway, platelet dysfunction, complement activation (not shown), and hyperimmune response)