Abstract
In cases of unilateral renal artery stenosis, acute exacerbations may present as hyponatremic hypertensive syndrome (HHS), a rare and highly morbid complication. Its insidious onset, low incidence, and often counter-intuitive laboratory profile can delay diagnosis and worsen outcomes. Furthermore, complications including end-organ ischemia, polyelectrolyte derangement, and hypertensive crises can occur. Herein, we present a 62-year-old man with known right renal artery stenosis who presented with HHS in hypertensive emergency with encephalopathy. Consideration of the underlying pathomechanism and careful fluid and electrolyte repletion can minimize complications and improve clinical outcomes in this highly morbid and precarious clinical syndrome.