Primary: Elevated PTH that results in elevated Ca2+. Typically caused by parathyroid adenoma.
Secondary: Elevated PTH due to Low Ca2+ (Hypocalcemia). Seen commonly in chronic kidney disease causing low Vitamin D synthesis and hyperphosphatemia. Also seen in several malabsorptive states (i.e chronic pancreatitis).
Tertiary: Elevated PTH due to hyperplasia/ hypersecretion from the paraythroid gland in the setting of long-standing secondary hyperparathyroidism (i.e CKD). This results in elevated PTH AND elevated Ca2+, even after correction of the secondary cause.
- Pitt SC, Sippel RS, Chen H. Secondary and Tertiary Hyperparathyroidism, State of the Art Surgical Management. The Surgical clinics of North America. 2009;89(5):1227-1239. doi:10.1016/j.suc.2009.06.011.
- Ahmad R., Hammond JM. Primary, secondary, and tertiary hyperparathyroidism. Otolaryngol Clin North Am. 2004 Aug;37(4):701-13, vii-viii.
- Russell RI. Hypoparathyroidism and malabsorption. British Medical Journal. 1967;3(5568):781-782.