A condition characterized by endothelial damage caused by a returning blood supply after a period of ischemia (e.g., myocardial infarction, ischemic stroke). Causes increased capillary permeability, tissue swelling, and release of reactive oxygen species. Extensive reperfusion injury (reperfusion syndrome) is associated with systemic disturbances such as acidemia, hyperkalemia (which can cause cardiac arrhythmias), and edema (which can cause compartment syndrome).