A patient who presents with refractory hypertension may have a curable underlying cause, such as Conn's syndrome. Because hypertension may be the only presenting sign of this disorder, a high index of suspicion is required. Detection of elevated aldosterone levels after salt loading and of abnormally suppressed plasma renin activity aids in the diagnosis. Conn's syndrome is caused by unilateral adrenal adenoma, which can be removed surgically. Aldosteronism due to bilateral adrenal hyperplasia can be managed with sodium restriction and use of potassium-sparing diuretics.