Causes

• Most common - removal of parathyroid glands during surgery
• Autoimmune polyendocrine syndrome type 1 - destroys parathyroid glands
• Genetic causes:
  • DiGeorge syndrome (parathyroid glands can’t produce enough PTH)
  • Autosomal dominant hypoparathyroidism - mutation in PTH calcium sensing receptor
• Pseudohypoparathyroidism Type 1a - Bones and kidneys don’t respond to the PTH due to a defect in their hormone receptor

Clinical features

• tetany - involuntary muscle contractions
• parasthesia
• changes in cardiac output
• calcification in basal ganglia/eye
• Chvistek’s and Trousseu’s sign

Severe complications

• seizures
• cardiac arrhythmias

Investigations

Beside:

• ECG - prolonged QT, ST, arrhythmias