Initial evaluation of hypercalcemia*

PTH: parathyroid hormone; FHH: familial hypocalciuric hypercalcemia; PTHrP: parathyroid hormone-related protein.

* The normal range for serum calcium is approximately 8.6 to 10.2 mg/dL (2.15 to 2.54 mmol/L). Interpretation of a specific abnormal test result should be based upon the reference range reported with that result. Measured calcium concentration should be corrected for any abnormality in serum albumin.

¶ Treatment should never be delayed if blood for diagnostic studies cannot be collected.

Δ Some medications associated with hypercalcemia include thiazide diuretics, lithium, teriparatide, abaloparatide, excessive vitamin A, and excessive theophylline. If possible, any medication or supplement that may be causing hypercalcemia should be discontinued.

◊ Serum PTH typically <20 pg/mL in an assay whose normal range is 10 to 60 pg/mL.