What is the mechanism of hypercalcemia and its consequences in primary hyperparathyroidism
PTH causes hypercalcemia by stimulating osteoclastic bone resorption and by increasing kidney calcium reabsorption in the distal nephron.
PTH also stimulates 1,25D synthesis, which leads to increased intestinal calcium absorption and increased calcium reabsorption in the distal nephron.
Hypercalcemia will increase the filter load of calcium, exceeding the tubular reabsorption capability and causing hypercalciuria and increased kidney stones.
