Which statement best describes the major renal manifestations of primary hyperparathyroidism?

Which statement best describes the major renal manifestations of primary hyperparathyroidism?

• A. Hyperkalemia
• B. Hypercalciuria and nephrolithiasis
• C. Hypocalciuria
• D. Anemia

Answer: (B)

In primary hyperparathyroidism, the key renal finding is hypercalciuria that can lead to nephrolithiasis. Elevated parathyroid hormone from an overactive gland increases calcium released from bone and absorbed from the gut, raising serum calcium. The kidneys filter this excess calcium, and while PTH helps conserve calcium in the distal tubule, the sheer load of filtered calcium results in higher calcium in urine. This excess urinary calcium can crystallize and form stones in the kidneys. So the combination of increased calcium in the urine and stone formation is the classic renal manifestation. Hyperkalemia and anemia aren’t typical features of this condition, and hypocalciuria would contradict the usual increase in urinary calcium.

In primary hyperparathyroidism, the key renal finding is hypercalciuria that can lead to nephrolithiasis. Elevated parathyroid hormone from an overactive gland increases calcium released from bone and absorbed from the gut, raising serum calcium. The kidneys filter this excess calcium, and while PTH helps conserve calcium in the distal tubule, the sheer load of filtered calcium results in higher calcium in urine. This excess urinary calcium can crystallize and form stones in the kidneys. So the combination of increased calcium in the urine and stone formation is the classic renal manifestation. Hyperkalemia and anemia aren’t typical features of this condition, and hypocalciuria would contradict the usual increase in urinary calcium.