von Willebrand Disease is one of the most common congenital bleeding disorders, but sometimes difficult to diagnose and treat. Acquired forms are less common, but probably underdiagnosed. Thrombotic thrombocytopenic purpura, linked to von Willebrand Disease through the common pathogenetic involvement of von Willebrand Factor, is rare, but usually fatal if not diagnosed and managed correctly. Following the fascinating historical introduction, this monograph presents the current understanding of von Willebrand Factor structure and function, the pathogenesis, classification, diagnosis and treatment of von Willebrand Disease, including congenital and acquired forms, and dedicates a chapter to thrombotic thrombocytopenic purpura. This textbook deals with any arising clinical and laboratory problems, while also representing a useful reference text to consult for detailed information and support when dealing with a suspected case.