Hypoparathyroidism
Hypoparathyroidism is insufficient parathyroid hormone, leading to low calcium and high phosphate, per 2025 international best-practice recommendations.
Symptoms
Muscle cramps, tingling around the mouth and in the fingers, muscle spasms, and fatigue; severe cases can cause seizures.
Causes and risk
Prior neck surgery (especially thyroid surgery) causes 75-80% of cases; autoimmune destruction and genetic causes account for the rest.
How it is evaluated
Low calcium with a low or inappropriately normal PTH, confirmed on two occasions at least 2 weeks apart, per international consensus criteria.
Treatment
Calcium supplementation plus active vitamin D (calcitriol) is first-line. Recombinant PTH replacement (including newer options like palopegteriparatide) is reserved for those with inadequate control on conventional therapy.
When to seek care
Tetany (muscle spasms), seizures, or laryngospasm from severe low calcium are emergencies requiring immediate IV calcium treatment.