Looking Beyond Blood Pressure: A Case-Based Approach to Primary Aldosteronism

Primary aldosteronism is an underrecognized cause of secondary hypertension, particularly when blood pressure elevation is not resistant and classic features are subtle. We describe a 63-year-old man with long-standing hypertension who presented with generalized weakness and was found to have persistent mild hypokalemia, proteinuria, and concentric left ventricular hypertrophy that appeared disproportionate to the degree of blood pressure elevation. These findings prompted evaluation for primary aldosteronism. Aldosterone-renin ratio testing, performed after correction of hypokalemia and interpreted in the context of ongoing antihypertensive therapy, demonstrated inappropriately elevated aldosterone with suppressed renin. Imaging revealed a unilateral adrenal lesion consistent with an adrenal adenoma. The patient declined surgical intervention and was managed medically with mineralocorticoid receptor antagonist therapy. This resulted in normalization of serum potassium, improved blood pressure control, resolution of proteinuria, and loss of renin suppression on follow-up. This case emphasizes the importance of maintaining a high index of suspicion for primary aldosteronism even when hypertension is not resistant, particularly when mild to moderate blood pressure elevation is accompanied by spontaneous hypokalemia and evidence of renal or cardiac target-organ involvement. An individualized, physiology-based diagnostic approach may facilitate earlier recognition of excess aldosterone and help prevent progression to resistant hypertension and long-term cardiovascular and renal complications.