Hypercalcemia is a metabolic abnormality with widespread effects. Mild or chronic persistent hypercalcemia may be asymptomatic, whereas acute onset hypercalcemia may present with musculoskeletal, gastrointestinal, and psychiatric changes. If a patient is taking calcium supplements and has a test result bordering on hypercalcemia, testing should be repeated after cessation of supplementation. Accurate calcium testing includes correction with a concurrent albumin concentration. Testing for ionized calcium can remove variability due to albumin or confirm a possible abnormal value. Confirmed high serum calcium is frequently associated with hyperparathyroidism or undetected cancer. Laboratory testing includes parathyroid hormone (PTH) testing, testing to identify organ involvement, and, in the event of low PTH, testing for cancer.
Last Update: June 2019