How does aldosterone regulate the body’s salt and water balance?

Aldosterone is a steroid hormone secreted by the adrenal glands that serves as the primary regulator of the body’s salt and water balance.1

Its regulation of these electrolytes occurs through the following biochemical process:

• Activation: Aldosterone binds to and activates specific receptors within the cytoplasm of renal tubular cells in the kidneys.12
• Ion Channel Stimulation: Once activated, these receptors stimulate the production of ion channels in the renal tubular cells.12
• Sodium and Water Retention: These channels facilitate the reabsorption of sodium ions from the urine back into the blood. Because water follows sodium, this process effectively increases the retention of both salt and water in the body.13
• Potassium Excretion: Simultaneously, the hormone promotes the excretion of potassium and hydrogen ions into the urine, maintaining electrolyte balance.134

The production of aldosterone is controlled by the renin-angiotensin system, which responds to fluctuations in blood pressure and plasma sodium levels.13