VWF and hyperthyroidism: Humans with hyperthyroidism are procoagulant as evidenced by increased factor VIII, IX, von Willebrand factor (vWf), fibrinogen, and plasminogen activator inhibitor 1 (PAI-1) which can lead to increased thrombus formation [9], while humans with hypothyroidism are hypocoagulant due to decreased FVIII, vWf and fibrinogen which can lead to increased bleeding tendency [10-12].