Renovascular hypertension: a rare cause of neonatal salt loss.

We report a case of severe hypertension in the newborn period due to obstruction of the right renal artery. The baby presented with polyuria leading to dehydration and was found to have hyponatraemia and severe renal salt loss. When sudden malignant hypertension is induced in experimental conditions, a high pressure diuresis and increased angiotensin II production are found. These findings could explain the renal salt loss, notwithstanding the effects of secondary hyperaldosteronism and hyper-reninaemia.