<unk>  is excessive production of parathyroid hormone (PTH) by the parathyroid glands.
Hyperparathyroidism
Pseudohyperparathyroidism
Secondary hyperparathyroidism
Hypoparathyroidism
Renal osteodystrophy
Parathyroid disease
Primary parathyroid hyperplasia
Pseudohypoparathyroidism