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Renal Sodium Retention

Meaning

Renal sodium retention is the physiological process where the kidneys increase the reabsorption of sodium ions (Na+) from the tubular fluid back into the bloodstream, thereby decreasing the amount of sodium excreted in the urine. This retention is a fundamental mechanism for maintaining the body’s fluid volume and systemic blood pressure, as water passively follows the osmotic gradient created by the retained sodium. In a clinical context, excessive or inappropriate sodium retention can contribute directly to hypertension and edema, particularly in conditions involving hormonal imbalances or heart failure.