Hyperparathyroidism (and hypercalcemia)

Page most recently updated 7 September 2026

This page focuses on the reported psychiatric associations, which may be the initial presenting manifestation, and on other clinical features that may assist the psychiatrist or primary care physician in identifying the underlying diagnosis, considered through the lenses of the diagnostic lenses framework.

Hyperparathyroidism is an endocrine disorder characterized by excessive parathyroid hormone activity, with multisystemic effects that vary according to the underlying cause and associated calcium disturbance.

It can present with psychiatric features when associated with hypercalcaemia, i.e., in primary or tertiary hyperparathyroidism. These features may include depression, anxiety, irritability, apathy, cognitive impairment, fatigue, sleep disturbance, and, less commonly, psychosis. Severe hypercalcaemia may additionally cause confusion or delirium.

Other characteristic features include cognitive slowing, weakness, fatigue, headache, and, with more severe hypercalcaemia, neuromuscular dysfunction and altered consciousness. Chronic hyperparathyroidism may be clinically subtle, with neuropsychiatric symptoms sometimes preceding recognition of the underlying calcium disorder.

From a multisystemic lens perspective, clinical features in other body systems include (but are not limited to):

  • Cardiovascular: hypertension, shortened QT interval, and, in significant hypercalcaemia, cardiac arrhythmias may occur.

  • Renal/electrolytes: hypercalcaemia and hypercalciuria are characteristic; polyuria, polydipsia, nephrolithiasis, nephrocalcinosis, and renal impairment may occur.

  • Gastrointestinal: anorexia, nausea, vomiting, constipation, abdominal discomfort, and, less commonly, pancreatitis may occur with hypercalcaemia.

  • Endocrine: hyperparathyroidism may be primary, secondary, or tertiary. Primary hyperparathyroidism typically causes hypercalcaemia, whereas secondary hyperparathyroidism is usually a compensatory response to chronic hypocalcaemia or impaired vitamin D metabolism and typically occurs with low or normal calcium levels; tertiary hyperparathyroidism may result in hypercalcaemia after prolonged secondary hyperparathyroidism.

  • Musculoskeletal: proximal muscle weakness, bone pain, reduced bone mineral density, osteoporosis, and fragility fractures may occur; skeletal involvement is particularly characteristic of more established primary hyperparathyroidism.

Early diagnosis is important to identify and treat hypercalcaemia and its underlying cause, prevent renal and skeletal complications, reduce cardiovascular and neurological complications, and recognize potentially reversible neuropsychiatric manifestations.

Selected references and further reading — Multisystemic lens

Cardinal RN, Bullmore ET. The diagnosis of psychosis. Cambridge: Cambridge University Press; 2011.

Sachdev PS, Keshavan MS, editors. Secondary schizophrenia. Cambridge: Cambridge University Press; 2010.

Levenson JL, editor. The American Psychiatric Association Publishing textbook of psychosomatic medicine and consultation-liaison psychiatry. 3rd ed. Washington (DC): American Psychiatric Association Publishing; 2019.

Stern TA, Beach SR, Smith FA, Freudenreich O, Vranceau AM, Fava M, editors. Massachusetts General Hospital handbook of general hospital psychiatry. 8th ed. Philadelphia: Elsevier; 2025.

Arciniegas DB, Yudofsky SC, Hales RE, editors. The American Psychiatric Association Publishing textbook of neuropsychiatry and clinical neurosciences. 6th ed. Washington (DC): American Psychiatric Association Publishing; 2018.

Agrawal N, Faruqui R, Bodani M, editors. Oxford textbook of neuropsychiatry. Oxford: Oxford University Press; 2020.

Boland R, Verduin M, editors. Kaplan and Sadock's comprehensive textbook of psychiatry. 11th ed. Philadelphia: Wolters Kluwer; 2024.

Loscalzo J, Fauci AS, Kasper DL, Hauser SL, Longo DL, Jameson JL, editors. Harrison's principles of internal medicine. 22nd ed. New York: McGraw Hill; 2025.