On the basis of histological and histochemical examinations of 100 postmortem observations of bacterial shock, 4 stages of disorders in the microcirculatory bed and in cell elements of organs in this complication are distinguished. The hemodynamic stage consists in redistribution of the blood flow, alternation of spasm and paresis, and vascular dystonia. In the stage of hemorheological disorders congestion is substituted by stasis, sludging of erythrocytes due to pachyemia. As a result of increased permeability of vessel walls, interstitial edema and early changes of parenchymatous cells of organs occur at the enzymatic level. The addition of DIBC syndrome leads to deeper ischemia of organs and formation of necroses, hemorrhages, acute ulcers. As a consequence, organ insufficiency (adrenal, renal, respiratory) develops.