Urinary sodium and phosphate excretion were studied in normotensive and hypertensive individuals during prolonged infusion with normal saline before and after the addition of 10% glucose. The results show a dichotomy between the enhanced fractional sodium excretion in the hypertensive subjects and the fractional phosphate excretion, which tended to be lower in this group than in normotensive subjects. These findings suggest an alteration of distal sodium reabsorption as the cause of the ‘exaggerated’ natriuresis of hypertensive subjects following saline infus