In primary hyperaldosteronism, which statement is true?

• A. High plasma renin that rises with volume depletion
• B. Low plasma renin that fails to rise with volume depletion
• C. Normal renin
• D. No change in renin

Answer: (B)

Autonomous aldosterone production drives sodium retention and expands the extracellular fluid, which suppresses renin release from the kidney. The result is a low plasma renin level that does not rise even when volume depletion would normally stimulate renin. This inappropriately blunted renin response distinguishes primary hyperaldosteronism from other forms where renin is elevated. Clinically, this pattern underpins the aldosterone-to-renin ratio used to diagnose the condition.