Abstract: The invention relates to an in-vitro method for diagnosing Von Willebrand Disease (VWD) and an increased bleeding risk associated with Von Willebrand Disease and/or acquired or congenital platelet function defects that reduce the interactions of Von Willebrand Factor (VWF) with platelets. The in-vitro method of the invention may also be used to diagnose further bleeding risks. The test is suitable for use as a screening test based on whole blood and has the additional benefit of being suitable as a point of care test. The method involves the incubation of a sample containing platelets and hemostasis factors with an activator of platelet aggregation and the measurement of the viscoelastic change after inducing coagulation, e.g., by means of thromboelastography (TEG).