Based on the reported data and observation of 86 patients with different forms of systemic vasculitis (SV) the authors analyzed the leading pathogenetic mechanisms of generalized vascular injuries seen in these diseases. The data presented attest to the role of disorders of immunoregulation, immune complex reactions, an increase in the blood coagulation potential, a rise of platelet and red cell aggregation in the pathogenesis of the main clinical syndromes of SV. At the same time the authors describe in detail the microcirculatory disorders seen in the main disease entities and discuss the concrete reasons for the development of capillarotrophic insufficiency and marked tissue hypoxia. Close interaction of the main pathogenetic factors of SV and the character of the disorders determine the necessity of a differentiated approach to the problems of the treatment of patients depending on the disease entity and the leading pathogenetic components.