Increased Serum Aldosterone

Differential Diagnosis

Primary hyperaldosteronism

Secondary hyperaldosteronism

Suggested Additional Lab Testing

Primary hyperaldosteronism

• Serum potassium is usually low, but a low-sodium diet may result in a normal value.

• Serum sodium is mildly elevated in most cases.

• Plasma renin activity is low for most cases of hyperaldosteronism.

• The low value for plasma renin makes the ratio of serum aldosterone to plasma renin very elevated in primary hyperaldosteronism.

Secondary hyperaldosteronism

• Serum potassium is usually low, but a low-sodium diet may result in a normal value.

• Normal to mildly elevated serum sodium

• Plasma renin activity is elevated when there is decreased perfusion of the kidneys, a common cause of secondary hyperaldosteronism