Hyperparathyroidism can cause which complications?

• A. Osteoporosis and nephrolithiasis
• B. Hypercalcemic crisis
• C. Hypophosphatemia
• D. Hypocalcemia

Answer: (A)

Excess parathyroid hormone drives both bone loss and high calcium in the body. PTH stimulates osteoclasts, increasing bone resorption and weakening bones over time, which leads to osteoporosis. At the same time, it raises serum calcium by increasing renal calcium reabsorption and promoting intestinal calcium absorption, while promoting phosphate excretion. The net effect is calcium-rich urine, which can crystallize and form kidney stones (nephrolithiasis). These two outcomes—bone demineralization and stone formation—are classic, well-recognized complications of hyperparathyroidism, making them the best choice.

Hypercalcemic crisis can occur but is an acute, less common presentation rather than a typical chronic complication. Hypophosphatemia can happen because of phosphate wasting, but it’s a metabolic consequence rather than a primary complication, and hypocalcemia is not typical since calcium tends to be elevated in this condition.