As a result of the study of 9 anuric patients, I believe that death from anuria usually is due to the disorganization of the structure of the internal environment and not to the accumulation of urea or hypothetic toxins. Therefore the rational approach is to preserve the normal volume and composition of the body fluids.In the presence of anuria and in the absence of intake of food and fluids, the volume of body water will be progressively reduced through insensible expenditure by way of the lungs and the skin, and the concen¬ trations of body fluid electrolytes will rise unless, as is occasionally the case, losses occur in vomitus and in diarrheal stools. Owing to consump¬ tion of body protein, the quantity of the products of the oxidation of pro¬ tein in the body fluids will be increased and their concentrations will, therefore, rise more extensively than those of the electrolytes. It is also evident that an intake of protein will add to the accumulation of nitrog¬ enous end products. On the other hand, if one provides a water intake which is larger than the insensible expenditure, the concentrations of the electrolytes will fall below their physiologic values.