Severe Hypercalcemia Caused by Calcium-Alkali Syndrome after 15 Years of Postoperative Hypoparathyroidism in a Patient with Undiagnosed Hyperaldosteronism.

Although seldom described, the calcium-alkali syndrome is an expected complication for individuals with postoperative hypoparathyroidism, as they require lifelong calcium and vitamin D supplementation. This case also shows the importance of hydrochlorothiazide use and primary aldosteronism as possible triggers of life-threatening hypercalcemia.