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    Cardiovascular, Critical Care / Resuscitation, Gastrointestinal, Metabolic / Endocrine, Urological

    Last Updated May 31, 2023
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    By Julian Marsden, Alexander Forrester

    First 5 Minutes

    Hypercalcemia crisis (serum calcium > 2.9 mmol/L) can lead to coma and acute renal failure. [1] [2]

    Consider Hyperparathyroidism [3] [4]: “Stones, bones, groans, psychiatric overtones.”

    • History of kidney stones.
    • Bone pain.
    • Gastrointestinal Symptoms (constipation, nausea, vomiting, anorexia).
    • Confusion, depression, memory loss.


    Parathyroid hormone (PTH) maintains serum calcium homeostasis [4].

    Normal serum calcium (corrected) = 2.1-2.6 mmol/L [3].


    Primary Hyperparathyroidism [2] [4] [5] [6]

    • Inappropriate secretion of PTH by the parathyroid gland.
    • Most common cause of hypercalcaemia.
    • Peak age 50-60, male to female ratio 3.5:1.
    • Most common in postmenopausal women.
    • Risk Factors:
      • Prolonged use of furosemide.
      • Hx of neck radiation therapy.
      • Lithium therapy.
    • Causes:
      • Adenoma – 85%
      • Carcinoma – <1%

    Secondary Hyperparathyroidism

    • Parathyroid hyperplasia resulting from continual PTH production from low calcium (and high phosphorus).
    • Causes:
      • Vitamin D deficiency ~ 50%
      • Chronic kidney disease (CKD) ~ 15%
      • Reduced intestinal absorption (IBD, celiac, surgery)

    Diagnostic Process

    In the emergency department, identification of severe hypercalcaemia is key.

    Figure 2 provides a simplified overview for diagnosis of hyperparathyroidism. Note, Definitive hyperparathyroidism diagnosis not usually established in the ED.

    Figure 2. Simplified diagnostic approach for Hyperparathyroidism [2] [3] [4] [7].

    Table 1. Common findings for primary and secondary hyperparathyroidism [2] [4] [7] [8]

    Recommended Treatment

    Treat hypercalcemia [3]:

    • Increase Ca excretion:
      • Normal Saline IV Fluids at 200-300mL/hr to promote renal elimination of Ca.
      • Loop diuretics, decrease resorption of Ca.
      • Hydrocortisone 100mg QID, inhibits effect of Vit D, decrease intestinal absorption of Ca, increase renal elimination of Ca, inhibit osteoclast-activating factor.
    • Reduce Ca release:
      • Calcitonin lowers Ca within 24-48 hours.
      • Bisphosphonates (pamidronate 90mg IV), potent inhibitors of osteoclast activity.
    • Others:
      • Stop taking drugs that increase Ca, i.e. thiazides, vitamin A and D, and Ca supplements.
      • Correct potassium and magnesium level.

    The definitive treatment for primary hyperparathyroidism is surgery.

    Criteria For Hospital Admission

    • Severe hypercalcemia.
    • Renal failure.
    • Altered mental status.
    • Severe dehydration.
    • Cardiac complications.

    Criteria For Transfer To Another Facility

    Acute presentation cannot be managed at the current facility.

    Criteria For Close Observation And/or Consult

    • Clinically unstable.
    • Severe hypercalcemia.

    Criteria For Safe Discharge Home

    • Clinically stable.
    • Follow up possible with Family physician for confirmation or endocrinology.

    Quality Of Evidence?


    Risk factors, causes, complications, and treatment of primary hyperparathyroidism are well established. Quality of evidence high.


    Due to variable causes, complications and presentations of secondary and other non-PTH mediated forms of hyperparathyroidism, quality of evidence is moderate.


    Related Information


    Reference List

    1. Wallace. Lecture: Parathyroid Basics and Clinical Scenarios in Parathyroid Disease. MEDD 412 2023. Vancouver, British Columbia, Canada: University of British Columbia Medical Program.

    2. Pokhrel et al. Primary Hyperparathyroidism. Retrieved from In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing 2022. https://www.ncbi.nlm.nih.gov/books/NBK441895/

    3. Nickson. Hypercalcaemia. Retrieved from Life in the Fastlane 2020. https://litfl.com/hypercalcaemia/

    4. Taneigra. Hyperparathyroidism. American Family Physician 2004, 69(2), 333-339.

    5. Jamal & Miller. Secondary and Tertiary Hyperparathyroidism. Journal of Clinical Densitometry 2013, 64-68. doi:0.1016/j.jocd.2012.11.012

    6. Melck. Lecture: Endocrine Surgery – Thyroid and Parathyroid. MEDD 412 2023. Vancouver, British Columbia, Canada: University of British Columbia Medical Program.

    7. Muppidi et al. Secondary Hyperparathyroidism. Retrieved from StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing 2023. https://www.ncbi.nlm.nih.gov/books/NBK557822/

    8. Norman Parathyroid Center. Secondary Hyperparathyroidism: Disease of the Parathyroid Glands Caused by Something Else 2023. Retrieved from Parathyroid.com: https://www.parathyroid.com/secondary-hyperparathyroidism.htm


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