The PTH is elevated due to decreased levels of calcium or 1,25-dihydroxy-vitamin D3. It is usually seen in cases of chronic kidney disease or defective calcium receptors on the surface of parathyroid glands.
Secondary hyperparathyroidism
Primary hyperparathyroidism
Tertiary hyperparathyroidism
Familial hypocalciuric hypercalcemia
Normophosphatemic familial tumoral calcinosis
Pseudohypoparathyroidism
Pseudopseudohypoparathyroidism
Parathyroid adenoma