This book covers widely the normal haemostatic mechanisms that maintain the circulatory blood in its fluid state and describe the processes of blood clot formation as a physiological response to vascular injury, and how these processes are limited to the site of vascular injury. Furthermore, this book gives detailed information about different types of stroke and particularly dealing with their causes and diagnosis taking in consideration the recent advances in the knowledge of thrombophilia at molecular basis. Moreover, in this book we present the results of our attempts to investigate the haemostatic causes of ischaemic stroke in Sudanese patients with especial emphasis to the common thrombophilic mutations (Factor V Leiden and prothrombin G20210A), and hyperfibrinogenaemia. In addition, to our attempt to verify the applicability of plasma D-dimer test for early diagnosis of ischaemia stroke.