Secondary and Tertiary Hyperparathyroidism.

Secondary hyperparathyroidism (SHP) is a frequent complication of kidney diseases. At variance with all the other forms of SHP, which are compensatory conditions, renal SHP has many pathogenetic peculiarities, which have been only in part defined. Furthermore, in the long course of chronic kidney diseases (CKD), SHP sometimes transforms into a hypercalcemic condition resembling the autonomous form of hyperparathyroidism (tertiary hyperparathyroidism; THP). The clinical consequences of SHP in CKD patients are manifold, encompassing not only bone and mineral disorders, but also other metabolic and organic changes which frequently burden these patients. Although the medical therapeutic tools have substantially increased in number and improved in their efficacy in recent decades, we have as yet no demonstration of a clear benefit regarding the major clinical outcomes. Furthermore, some of these patients, particularly when the autonomous THP develops, still require a surgical approach.