Aldosterone
The salt-water hormone. Aldosterone is a steroid hormone from the adrenal cortex that controls your body's sodium and potassium balance. It tells kidneys to retain sodium (and water) while excreting potassium. Critical for blood pressure, fluid balance, and mineral homeostasis.
What Aldosterone Does
Sodium Retention
Tells kidneys to reabsorb sodium. Water follows sodium, increasing blood volume.
Potassium Excretion
Exchanges sodium for potassium. K+ excreted in urine. Can cause low K if excess aldosterone.
Blood Pressure
More volume = higher pressure. Aldosterone blockers used for hypertension.
Acid-Base Balance
Promotes hydrogen ion excretion. Affects blood pH regulation.
Magnesium Excretion
Also increases magnesium loss. Chronic elevation depletes magnesium.
Cardiac Effects
Excess causes cardiac fibrosis. Aldosterone blockers cardioprotective.
The RAAS System
Renin-Angiotensin-Aldosterone System controls aldosterone release:
Aldosterone Imbalances
High (Hyperaldosteronism)
High blood pressure, low potassium, muscle weakness, frequent urination. Conn's syndrome is primary form.
Low (Hypoaldosteronism)
Low blood pressure, high potassium, salt craving, dehydration. Can occur in Addison's disease.