The hyponatremic hypertensive syndrome in renal artery stenosis: an infrequent cause of hyponatremia.

The hyponatremic hypertensive syndrome is a rare but serious complication of reno-vascular disease. The syndrome is characterized by hypertension and profound natriuresis, leading to body sodium and water depletion. Hypertension is typically refractory to treatment. We report an 82-year-old patient with this syndrome and describe the results of an audit of the clinical records of patients admitted to a teaching hospital over a two-year period with confirmed renal artery stenosis and hyponatremia. The syndrome should be suspected in patients in whom severe hypertension is associated with hyponatremia without other apparent cause, especially in the presence of reno-vascular disease.