Addison's disease affects sodium and potassium balance due to hypoaldosteronism. Which electrolyte pattern is typical?

• A. Low sodium and high potassium
• B. High sodium and low potassium
• C. Low sodium and low potassium
• D. High sodium and high potassium

Answer: (A)

Addison's disease lowers aldosterone, which normally promotes sodium reabsorption and potassium excretion in the distal nephron. Without enough aldosterone, sodium is lost in the urine leading to low serum sodium, while potassium is not adequately excreted, causing high serum potassium. This combination—low sodium with high potassium—is the typical electrolyte pattern.