Abstract
Plasma volume detns. in 5 under-wt. patients were higher than predicted values based on surface area, whereas in 5 obese individuals the reverse was true; much closer approx. was obtained when height was used in the prediction of normal values. Wt. loss and wt. gain in 3 patients studied were not accompanied by proportionate changes in plasma vol. In the presence of significant wt. loss or obesity, it is suggested that height or ideal wt. be employed to predict the normal plasma vol.