From secondary to tertiary hyperparathyroidism
This text in quotation is from the following citation.
“Patients with severe chronic kidney disease and secondary hyperparathyroidism usually have low or normal serum calcium concentrations but, with prolonged disease, may develop hypercalcemia. The rise in plasma calcium most often occurs in patients with adynamic bone disease and markedly reduced bone turnover. In such patients, hypercalcemia is due to a marked reduction in the bone uptake of calcium after a calcium load, as with calcium carbonate to treat hyperphosphatemia.
In other patients with advanced renal failure, hypercalcemia is due to progression from appropriate parathyroid hyperplasia to autonomous overproduction of PTH, a disorder called tertiary hyperparathyroidism.”
Elizabeth Shane, MD. Etiology of hypercalcemia. In: UpToDate, Post, TW (Ed), UpToDate, Waltham, MA, 2014.