The pathologic consequences of intensive care treatment are manifested locally and generally. Local disturbances due to intensive care therapy are as follows: blood vessel injury, thromboembolism caused by catheterization, tracheal stenosis following tracheostomy and, most important, sepsis. The more general pathologic results of intensive care treatment are essentially brought about by shock. Shock-kidney plays a subordinate role today because it is a reversible state of renal insufficiency. In contrast, shock-lung leads to death in about 50% of the cases. The pathohistologic features of the initial stages are microthrombosis, perivascular edema and endothelial damage. These three characteristics are already apparent before hospital admission and institution of treatment. It is not yet clear to what extent the therapy augments the pathologic changes or leads to clinically manifested symptoms.