Diagnosis of Hypertension Due to Renal Arterial Stenosis.

N 1962, we 1 published a report on the value of the comparative Usodium/Ucreatinine ratio in the diagnosis of hypertension due to renal arterial stenosis. This ratio is defined as the proportional relation between the concentration of sodium and creatinine (U5Odiu./Ucreatinine) in the urine issuing simultaneously from each ureter. We also suggested that routine performance of dehydrated-hydrated intravenous pyelography on all hypertensive patients would adequately exclude renal arterial stenosis as the cause of the elevated blood pressure. In the crucible of 1 year's time, these tenets have held. This paper extends these observations and appraises them more critically. It also describes a method whereby, without added discomfort to the patient, the difference in comparative Usodium/Ucreatinine ratio, in the presence of renal arterial stenosis, is greatly exaggerated by preceding the urine collection with a provocative infusion of hypertonic saline solution.