In Cushing's syndrome with aldosterone overproduction, which finding is expected?

• A. Edema
• B. Dehydration
• C. Hypokalemia
• D. Hypernatremia

Answer: (A)

The main idea is that excess mineralocorticoid activity causes the kidneys to retain sodium and water, which expands the extracellular fluid volume and leads to edema. In Cushing’s syndrome, very high cortisol can mimic aldosterone (through mineralocorticoid receptor activation when 11β-HSD2 is overwhelmed), promoting sodium reabsorption and water retention. That fluid overload commonly presents as edema. While potassium loss can occur with mineralocorticoid excess, the most overt and expected finding tied to this process is edema from increased circulatory volume. Dehydration would be unlikely because fluid is being retained, and although hypokalemia can accompany, edema best reflects the volume status change. Hypernatremia may accompany mineralocorticoid excess, but edema specifically highlights the fluid overload aspect clinicians monitor most directly.