Which statement about primary hyperaldosteronism is correct?

• A. It is renin-dependent
• B. It is renin-independent
• C. It is always due to an aldosteronoma
• D. It is primarily due to unilateral adrenal hemorrhage

Answer: (B)

Primary hyperaldosteronism is defined by autonomous production of aldosterone from the adrenal cortex, which raises sodium reabsorption and expands extracellular fluid, leading to hypertension and potassium loss. Because aldosterone is running out of regulatory control, the kidney senses the increased blood pressure and volume and suppresses renin release. The result is a low plasma renin activity, i.e., renin-independent aldosterone excess. This contrasts with secondary hyperaldosteronism, where renin is elevated and drives the increase in aldosterone.

Etiologies include either unilateral aldosterone-producing adenoma or bilateral adrenal hyperplasia; it is not limited to an aldosteronoma. Unilateral adrenal hemorrhage is not a typical cause of primary hyperaldosteronism.