Which electrolyte abnormalities are commonly seen in primary adrenal insufficiency?

• A. Hyponatremia and hyperkalemia
• B. Hypernatremia and hypokalemia
• C. Hypercalcemia and hypocalcemia
• D. Hypoglycemia only

Answer: (A)

When the adrenal cortex fails, there is a deficiency of aldosterone and cortisol. Aldosterone normally promotes sodium reabsorption and potassium excretion in the kidney. Without enough aldosterone, sodium is lost in the urine and water follows, leading to hyponatremia. At the same time, reduced potassium excretion causes hyperkalemia. This combination—low sodium and high potassium—is the classic electrolyte pattern in primary adrenal insufficiency. Cortisol deficiency can contribute to hypoglycemia, but that’s a separate metabolic effect rather than an electrolyte abnormality. The other patterns (hypernatremia with hypokalemia, calcium abnormalities, or hypoglycemia alone) don’t fit the typical aldosterone-driven changes seen here.