Practice Essentials
Primary hyperparathyroidism is one of the most common causes of hypercalcemia and should be considered in the differential of any individual presenting with an elevated calcium level.
Primary hyperparathyroidism (PHPT), hypersecretion of parathormone (parathyroid hormone: PTH) from the parathyroid glands, results in persistent hypercalcemia and usually hypercalciuria.
Rarely, PHPT manifests as a component of genetically transmitted endocrine diseases, specifically multiple endocrine neoplasia syndromes. PHPT causes symptoms in multiple organ systems throughout the body via its impact on calcium homeostasis. The most recognizable symptoms are renal and skeletal complications: nephrolithiasis, nephrocalcinosis, osteitis fibrosa cystica, and osteoporosis.
PHPT also manifests more subtly with nonspecific symptoms in other organ systems including: cardiovascular, gastrointestinal, rheumatic, and neuropsychiatric. Untreated PHPT can lead to irreversible changes including skeletal deformations and renal insufficiency.