PTH and primary hyperparathyroidism: Blood tests revealed increased levels of serum calcium of 12.8 mg/dL (normal, 9.0-10.6 mg/dL), incrased levels of parathyroid hormone (PTH) at 115 pg/mL (normal, 12-72 pg/mL), and a low serum phosphorus level of 2.4 mg/dL (normal, 2.5-4.5 mg/dL), findings suggestive for primary hyperparathyroidism.