Plasma Renin Test

This panel measures two hormones—aldosterone and renin—that work together to regulate blood pressure and fluid balance. Aldosterone is produced by the adrenal glands and increases sodium and water retention; renin is produced by the kidneys and activates this system. Abnormal ratios may indicate primary hyperaldosteronism (excess aldosterone), secondary hyperaldosteronism (from kidney or heart disease), or adrenal insufficiency. This test is typically ordered when evaluating resistant hypertension, persistent low potassium, or suspected adrenal disorders.