Etiology:

1. Removal of gland:
   • During thyroidectomy
   • Radical neck dissection
   • Resection of parathyroid mass/nodes
2. Congenital gland aplasia
3. Idiopathic gland atrophy
4. Primary adrenal insufficiency (usually with mucocutaneous candidiasis)

Clinical: Related to hypocalcemia

• Neuromuscular:
  • Tetany
  • Chvostek sign (facial nerve spasms)
  • Trousseau sign
  • Parkinson like movements
  • Papilloedema
• CNS: Emotional instability, anxiety, depression, hallucination, psychosis
• Eyes: Cataracts due to lens calcification
• CVS: Long QT interval
• Dental: General hypoplasia, failure of eruption

NB: Pseudohypoparathyroidism: Failure of 2nd messenger cAMP to respond to PTH

• Type 1: Albright syndrome
• Type 2: Defect in cAMP target tissue

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