The main aim of this thesis was to provide a systematic review of the complex pathophysiology of ischemia-reperfusion injury, and its effect on blood rheology and on the microcirculatory system. The phenomenon of ischemia-reperfusion injury is commonly witnessed in organ transplantation, major organ surgical resections and after shock, causing harmful local and systemic outcomes, and is associated with a high incidence of morbidity and mortality. Ischemic preconditioning, one of the most potent procedures that emerged to counteract ischemia-reperfusion injury, allows tissues to adapt and become tolerant to such conditions. Research has also more recently been conducted on a similar technique termed ischemic postconditioning, in which we have seen that timing to reperfusion is the key. Remote ischemic preconditioning, after application of brief ischemia-reperfusion cycles in a single organ, was found to provide systemic protection from a subsequent extensive period of ischemia. Similarly, remote ischemic postconditioning has also evolved as a protective measure. Ischemia-reperfusion affects the state of blood flow, at the microcirculatory level in many ways. However, the interactions between hemodynamic characteristics and alterations in hemorheology are complex and the effects of ischemia-reperfusion injury are difficult to determine because rheological properties of multiple blood elements are influenced simultaneously, each affecting different aspects of its rheological behavior, in turn.