Abstract
Hypercalcemia, and subsequently primary hyperparathyroidism, is discovered in two ways. Most commonly, hypercalcemia is discovered when serum calcium is measured as a screening test or in patients who have fatigue, weakness, or other symptoms of physical or neuropsychological disability. Much less often, it is discovered when serum calcium is measured in patients with nephrolithiasis or osteopenia, the two main complications of hyperparathyroidism. Unless the cause of the hypercalcemia is obvious — for example, the patient has cancer or is taking large doses of vitamin D — the next step is measurement of serum parathyroid hormone. A high or even inappropriately . . .