Recognize that hypercalcemia is most often asymptomatic but can be present in patients with nonspecific symptoms or unexplained dehydration and confusion.
Ask patients about history relevant to hypercalcemia including malignancy, nephrolithiasis, granulomatous disease, and endocrine tumors.
Measure serum calcium and albumin to diagnose hypercalcemia; diagnose hypercalcemia if the serum calcium level is ≥10 mg/dL.
Measure intact PTH to differentiate between parathyroid- and nonparathyroid-mediated disease.
If PTH levels are low, check other diagnostic tests to narrow the differential diagnosis, beginning with a malignancy work-up.
If PTH levels are high or inappropriately normal, check 24-hour urine calcium to differentiate between hyperparathyroidism and familial hypocalciuric hypercalcemia.