Primary hyperparathyroidism

Primary hyperparathyroidism is a disorder of bone mineralization and renal physiology due to excess parathyroid hormone secretion. Parathyroid hormone (PTH) is produced and released by the parathyroid chief cells, under regulation of the G- protein-coupled calcium-sensing receptor. Primary hyperparathyroidism occurs when there is a loss of the inhibitory feedback of PTH release by extracellular calcium. The rise in PTH levels is initially associated with a normal serum calcium, and then over time with hypercalcaemia. The most common cause of primary hyperparathyroidism is a benign solitary adenoma (80%). Other causes include multiple adenomas and hyperplasia. This chapter reviews the causes, clinical features, and management of primary hyperparathyroidism.