Abstract
The protean manifestations of sickle cell disease (SCD), especially, microvessel involvement in the vasoocclusive process, is classically ascribed to the phenomena of erythrocyte sickling and enhanced red cell-endothelial adherence. Pertubations in various hemostatic systems occurs in SCD, both in steady state and during vasoocclusion, with the intravascular generation of thrombin. The etiology(s) of thrombin generation in SCD will be described. Whether the activation of the cellular and plasmatic phases of hemostasis is causative or occurs as a result of vascular injury will be discussed.