Secondary hyperparathyroidism

Abstract

Elevated parathyroid hormone (PTH) levels in the presence of normal concentrations of serum calcium and phosphorus more often represent physiologic compensation or secondary hyperparathyroidism (SHP) than primary parathyroid gland hyperfunction. In such scenarios, mild disorders of calcium or phosphorus homeostasis due to inadequate intake, absorption, mobilization, or excretion should be suspected clinically but may yet require comprehensive testing of nutritional status, organ function, or hormonal status to detect or confirm. Treatment of factors suspected of causing SHP can be therapeutic and diagnostic or, if ineffective, raise the possibility of parathyroid gland autonomy or impaired PTH action. In contrast, premature pursuit of parathyroid imaging or surgical management designed to evaluate and manage primary hyperparathyroidism may yield inaccurate diagnoses, lead to ineffective therapy, or further derange mineral homeostasis by compromising a necessary, compensatory increase in serum PTH concentration.