Schematic representation of pathophysiological mechanisms (described or postulated) leading to activation of coagulation in sickle cell disease. Based on Virchow’s triad, the illustrated pathways contribute to activation of coagulation (and possibly eventual thrombosis) by one of three broad mechanisms: (1) changes in the vessel wall; (2) changes in blood flow; and/or (3) changes in the composition of blood components (‘hypercoagulability’). The numbers refer to the specific reference describing the particular pathway (represented by a joining arrow); references are listed at the end of the text.

Abbreviations: NO, nitric oxide; PS, phosphatidylserine; RBC, red blood cell; MPs, microparticles; TF, tissue factor; SCD, sickle cell disease