A patient presents with Addison disease. Serum sodium and potassium analyses are performed. What would the results reveal?

A patient presents with Addison disease. Serum sodium and potassium analyses are performed. What would the results reveal?

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

Answer: (C)

When adrenal cortex function is lost in Addison disease, aldosterone production falls. Aldosterone normally signals the kidneys to reabsorb sodium and excrete potassium. With its deficiency, you lose sodium in the urine (and along with it water), producing hyponatremia and volume depletion, while potassium is not excreted efficiently and builds up in the blood, causing hyperkalemia. So the expected serum pattern is low sodium with high potassium.

When adrenal cortex function is lost in Addison disease, aldosterone production falls. Aldosterone normally signals the kidneys to reabsorb sodium and excrete potassium. With its deficiency, you lose sodium in the urine (and along with it water), producing hyponatremia and volume depletion, while potassium is not excreted efficiently and builds up in the blood, causing hyperkalemia. So the expected serum pattern is low sodium with high potassium.