History and exam

Key diagnostic factors

common

history of thyroid, parathyroid, or laryngeal surgery

Post-surgical hypoparathyroidism is the major aetiology in adults.[1]

chronic alcoholism

Chronic alcoholism causes magnesium wasting through renal mechanisms exacerbated by poor nutrition.[16][17]

malnutrition, malabsorption, diarrhoea

Malnutrition, malabsorption, and diarrhoea can produce hypomagnesaemia.[16][17]

muscle twitches, spasms, cramps

Muscle cramping, stiffness, and tetany may indicate chronic and/or mild hypocalcaemia.

paraesthesias, numbness, tingling

Intermittent or persistent paraesthesia, numbness, or tingling may indicate acute or severe hypocalcaemia. Chronic hypocalcaemia may manifest as perioral and distal hand and foot paraesthesias.

poor memory, slowed thinking

Can manifest with any degree of hypocalcaemia.

uncommon

Chvostek's sign

Ipsilateral contraction of facial muscles when facial nerve is tapped in front of the ear. Chvostek's sign: a video demonstration Opens in new window

convulsions

Usually generalised. May indicate acute or severe hypocalcaemia.

irregular heart beat, tachycardia

Acute or severe hypocalcaemia can cause prolonged QT interval on ECG, irregular heart beat, tachyarrhythmias, hypotension.[Figure caption and citation for the preceding image starts]: ECG demonstrating an atrial arrhythmia most likely to be atrial fibrillation in a patient with hypoparathyroidism and hypocalcaemiaAdapted from Nijjer S, Ghosh AK, Dubrey SW. Hypocalcaemia, long QT interval and atrial arrhythmias. BMJ Case Reports 2010 [doi:10.1136/bcr.08.2009.2216]. Copyright © 2011 by the BMJ Publishing Group Ltd. [Citation ends].com.bmj.content.model.Caption@50fcb5f3

Trousseau's sign

Painful clasping response of fingers and hands when blood pressure cuff is inflated above systolic blood pressure. Trousseau's sign: video clip Opens in new window

Other diagnostic factors

common

anxiety

May be due to hyperventilation, which can worsen symptoms of hypocalcaemia because alkalosis will lower serum fraction of ionised calcium.

dry hair, brittle nails

Chronic hypocalcaemia.[Figure caption and citation for the preceding image starts]: Nail dystrophy due to hypocalcaemiaNijjer S, Ghosh AK, Dubrey SW. Hypocalcaemia, long QT interval and atrial arrhythmias. BMJ Case Reports 2010 [doi:10.1136/bcr.08.2009.2216]. Copyright © 2011 by the BMJ Publishing Group Ltd. [Citation ends].com.bmj.content.model.Caption@7d8491ca

cataracts

Common after long-standing hypocalcaemia in congenital forms of hypoparathyroidism.

uncommon

history of mucocutaneous candidiasis

Autoimmune polyendocrine syndrome type 1 (APS1) presents as mucocutaneous candidiasis in the first few years of life, followed by hypoparathyroidism and/or adrenal insufficiency, typically with onset in childhood.[12]

history of chronic transfusions in patients with thalassaemia

Transfusional iron overload may occur in patients with thalassaemia after many years of transfusions without adequate chelation therapy.

dyspnoea

Can be due to wheezing, congestive heart failure, or laryngeal constriction; requires urgent assessment and treatment.

laryngeal spasm

Can be caused by acute or severe hypocalcaemia. It is a medical emergency that can be life-threatening if left untreated.

Risk factors

strong

thyroid surgery

Extensive surgery, such as total thyroidectomy for cancer, and lymph node dissection; prior surgery in the cervical area; less experienced surgeon.[21]

parathyroid surgery

Prior surgery in the cervical area, especially prior parathyroidectomy; less experienced surgeon.

Risk factors for transient hypoparathyroidism include: extent of parathyroid exploration; moderate hypercalcaemia as an indication for parathyroid surgery (with the possibility of suppression of remaining normal gland[s] by prevailing hypercalcaemia).[22]

hypomagnesaemia

Excessive, chronic alcohol intake; poor nutrition; chronic diarrhoea and malabsorption; post-small intestine surgery; and certain drugs such as proton pump inhibitors.[14][15][16]

moderate and chronic maternal hypercalcaemia (neonatal hypocalcaemia)

Strong propensity to suppress neonatal parathyroid function.

autosomal dominant conditions (e.g., mutations in CASR, GATA3)

Chance of offspring being affected is 50%.[10][11]

weak

hereditary haemochromatosis

Hypoparathyroidism is a late manifestation after extensive iron deposition in tissues has occurred (e.g., liver, heart, pituitary gland).

transfusional iron overload in thalassaemia

Seen after many years of transfusions without adequate chelation therapy.

Wilson's disease

Copper deposition is a rare cause of hypoparathyroidism.

metastatic cancer

Hypoparathyroidism due to tumour infiltration or radiotherapy is a very rare manifestation.

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