In hypoparathyroidism the parathyroid glands make too little parathyroid hormone, so blood calcium falls and phosphate rises. The most common cause is damage to or removal of the glands during neck surgery, followed by autoimmune disease.
Key symptoms
- Tingling around the mouth and in the fingers and toes
- Muscle cramps and spasms
- Fatigue, anxiety or low mood
- Seizures in severe cases
- Brain fog and dry skin over time
What you find on exam
- Chvostek sign: facial twitch when tapping in front of the ear
- Trousseau sign: hand spasm with the blood pressure cuff inflated
- Scar from thyroid or neck surgery
- Wheeze or stridor from laryngeal spasm
- Cataracts in long-standing disease
Tests
- Low calcium, corrected for albumin, or low ionized calcium
- PTH low or inappropriately normal; high phosphate
- Magnesium level, since low magnesium blocks PTH
- ECG for a long QT interval; vitamin D, kidney function and urine calcium
Treatment basics
- Severe symptoms: IV calcium gluconate with cardiac monitoring
- Correct low magnesium first
- Long term: oral calcium carbonate or citrate plus calcitriol
- Aim for calcium in the low-normal range to protect the kidneys
- Replacement PTH (palopegteriparatide) for poorly controlled cases
Red flags
- Seizure, laryngospasm or tetany
- Long QT or arrhythmia on ECG
- Severe low calcium after recent neck surgery
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Sources: NCCPA PANCE Content Blueprint; NBOME COMLEX-USA clinical presentations; AAMC Core Entrustable Professional Activities (Core EPAs). Written by Making Synapses. Making Synapses is not affiliated with these organizations.