pPlatelets are critical elements in the blood stream, supporting hemostasis defense against bleeding, as well as performing even more complex tasks within networks of biological immunity and pathophysiological processes, such as cancer and ischemiareperfusion injury. Changes in the number and function of platelets may have a substantial impact on any of these processes. The simple finding of a reduced platelet count thrombocytopenia has a history origin and a consequence e.g., bleeding. This book brings together international experts to provide an up-to-date overview of the impact of thrombocytopenia from a clinical perspective.p