Hyperparathyroidism is an excess of parathyroid hormone in the bloodstream due to overactivity of one or more of the body's four parathyroid glands. These glands are about the size of a grain of rice and are located in your neck.

The parathyroid glands produce parathyroid hormone, which helps maintain an appropriate balance of calcium in the bloodstream and in tissues that depend on calcium for proper functioning.

Two types of hyperparathyroidism exist. In primary hyperparathyroidism, an enlargement of one or more of the parathyroid glands causes overproduction of the hormone, resulting in high levels of calcium in the blood (hypercalcemia), which can cause a variety of health problems. Surgery is the most common treatment for primary hyperparathyroidism.

Secondary hyperparathyroidism occurs as a result of another disease that initially causes low levels of calcium in the body and over time, increased parathyroid hormone levels occur.

May 19, 2017
  1. Primary hyperparathyroidism. National Institute of Diabetes and Digestive and Kidney Diseases. https://www.niddk.nih.gov/health-information/endocrine-diseases/primary-hyperparathyroidism. Accessed Feb. 28, 2017.
  2. El-Hajj Fuleihan G. Pathogenesis and etiology of primary hyperthyroidism. http://www.uptodate.com/home. Accessed Feb. 28, 2017.
  3. About the parathyroid glands. American Association of Clinical Endocrinologists. http://www.empoweryourhealth.org/endocrine-conditions/parathyroid. Accessed Feb. 28, 2017.
  4. Ferri FF. Pericarditis. In: Ferri's Clinical Advisor 2017. Philadelphia, Pa.: Elsevier; 2017. https://www.clinicalkey.com. Accessed Feb. 28, 2017.
  5. Abrams SA. Neonatal hypocalcemia. http://www.uptodate.com/home. Accessed Mar. 1, 2017.
  6. Jameson JL. Surgical management of hyperparathyroidism. In: Endocrinology: Adult and Pediatric. 7th ed. Philadelphia, Pa.; Saunders Elsevier. 2016. http://www.clinicalkey.com. Accessed Feb. 28, 2017.
  7. Wilhelm SM, et al. The American Association of Endocrine Surgeons guidelines for definitive management of primary hyperparathyroidism. JAMA Surgery. 2016;151:959.
  8. Hypoparathyroidism and hyperparathyroidism. National Health Service. http://www.nhs.uk/Conditions/hypoparathyroidism-hyperparathyroidism/Pages/Introduction.aspx. Accessed Feb. 28, 2017.
  9. Hormone replacement therapy. Micromedex 2.0 Healthcare Series. http://www.micromedexsolutions.com. Accessed March 1, 2017.
  10. Smoking and bone health. NIH Osteoporosis and Related Bone Diseases — National Resource Center. https://www.niams.nih.gov/Health_Info/Bone/Osteoporosis/Conditions_Behaviors/bone_smoking.asp. Accessed March 1, 2017.
  11. Calcium: Fact sheet for consumers. Office of Dietary Supplements. https://ods.od.nih.gov/factsheets/Calcium-Consumer/. Accessed March 1, 2017.
  12. Cinacalcet. Micromedex 2.0 Healthcare Series. http://www.micromedexsolutions.com. Accessed March 1, 2017.
  13. Nippoldt TB (expert opinion). Mayo Clinic, Rochester, Minn. March 4, 2017.