Last updated: April 5, 2023

Summarytoggle arrow icon

Hypoparathyroidism is an endocrinological disorder characterized by parathyroid hormone (PTH) deficiency. The most common cause of hypoparathyroidism is damage or injury to the parathyroid glands during anterior neck surgery, which leads to impaired PTH synthesis and/or secretion. Other causes include genetic conditions and autoimmune or infiltrative parathyroid gland destruction. Congenital disorders affecting parathyroid gland development typically manifest in childhood. Pseudohypoparathyroidism manifests similarly to hypoparathyroidism but is caused by resistance to PTH rather than insufficient hormone levels. Hypocalcemia is the primary manifestation of both hypoparathyroidism and pseudohypoparathyroidism, and can cause symptoms ranging from muscle cramps to seizures or heart failure. Chronic hypoparathyroidism can cause basal ganglia calcifications (resulting in extrapyramidal disorders), cataracts, and skeletal and dental abnormalities. The presence of hypocalcemia and concurrent low (or inappropriately normal) PTH levels on two separate occasions ≥ 2 weeks apart confirms the diagnosis. Management typically includes correcting hypocalcemia through calcium and vitamin D supplementation and monitoring for complications. PTH replacement therapy may be indicated in selected patients.

Etiologytoggle arrow icon

Consider hypoparathyroidism in patients who present with hypocalcemia after surgery for head and neck cancer, e.g., thyroidectomy. [2]

Clinical featurestoggle arrow icon

Acute manifestations [3]

The presence of the Chvostek sign or Trousseau sign in response to provocative maneuvers may help to identify latent tetany in patients with asymptomatic hypocalcemia. [4]

Chronic manifestations

Diagnosticstoggle arrow icon

Assess for hypoparathyroidism in patients with confirmed hypocalcemia and all patients after total thyroidectomy.

Laboratory studies [1]

Diagnostic confirmation

Both results must be present on two separate occasions, ≥ 2 weeks apart. [5]

  • Serum calcium: below the LLN
  • Serum intact PTH: low or inappropriately normal

Calcium levels respond to changes in PTH levels within minutes. To ensure accurate results, perform calcium and PTH studies concurrently.

Severe hypocalcemia is a medical emergency. Do not wait for confirmation of the underlying etiology to initiate treatment of hypocalcemia.

Additional studies [6]

The following findings help support the diagnosis, monitor for complications, and guide management.

Renal imaging [1]

Postthyroidectomy assessment [1]

  • Measure serum PTH levels 12–24 hours after total thyroidectomy.
  • Interpretation [1]
    • PTH < 10 pg/mL (1.05 pmol/L): Permanent hypoparathyroidism is possible.
    • PTH > 10 pg/mL (1.05 pmol/L): Permanent hypoparathyroidism is unlikely.

Differential diagnosestoggle arrow icon

See “Interpretation of laboratory findings in hypocalcemia.

Pseudohypoparathyroidism type 1A (PHP1A)


The differential diagnoses listed here are not exhaustive.

Treatmenttoggle arrow icon

All patients should receive conventional therapy with calcium and vitamin D supplementation. Refer to an endocrinologist for definitive management.

Treatment of hypocalcemia [2]

Pharmacotherapy [1][7]

Therapeutic regimens are adjusted and dosages titrated to achieve target serum levels.

Monitoring [1]

Regular follow-up studies facilitate early identification of complications.

Referencestoggle arrow icon

  1. Walls R, Hockberger R, Gausche-Hill M, Erickson TB, Wilcox SR. Rosen's Emergency Medicine 10th edition- Concepts and Clinical Practice E-Book. Elsevier Health Sciences ; 2022
  2. Khan AA, Bilezikian JP, Brandi ML, et al. Evaluation and Management of Hypoparathyroidism Summary Statement and Guidelines from the Second International Workshop. J Bone Miner Res. 2022.doi: 10.1002/jbmr.4691 . | Open in Read by QxMD
  3. Gafni RI, Collins MT. Hypoparathyroidism. N Engl J Med. 2019; 380 (18): p.1738-1747.doi: 10.1056/nejmcp1800213 . | Open in Read by QxMD
  4. Kumar V, Abbas AK, Aster JC. Robbins Basic Pathology. Elsevier ; 2018
  5. Jesus JE, Landry A. Chvostek's and Trousseau's signs. N Engl J Med. 2012; 367 (11): p.e15.doi: 10.1056/nejmicm1110569 . | Open in Read by QxMD
  6. Gilbert, SJ; Weiner, DE. National Kidney Foundation's Primer on Kidney Disease. Elsevier Health Sciences ; 2017
  7. Brandi ML, Bilezikian JP, Shoback D, et al. Management of Hypoparathyroidism: Summary Statement and Guidelines. J Clin Endocrinol Metab. 2016; 101 (6): p.2273-2283.doi: 10.1210/jc.2015-3907 . | Open in Read by QxMD
  8. Müller M. Chirurgie für Studium und Praxis (2012/13). Medizinische Verlags- und Informationsdienste ; 2011

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