Hypoparathyroidism: Symptoms, Causes, Diagnosis, and Treatment Guide

Hypoparathyroidism—deficient parathyroid hormone (PTH) production—leads to hypocalcemia and hyperphosphatemia, affecting nerves, muscles, bones, and the heart.

Causes

• Post-surgical (most common): Thyroidectomy, parathyroidectomy—accidental removal/devascularization of parathyroids.
• Autoimmune: Isolated or part of polyglandular autoimmune syndrome type 1 (APS-1).
• Genetic: CaSR activating mutations, GCM2 mutations, DiGeorge syndrome (22q11 deletion).
• Infiltrative: Hemochromatosis, Wilson disease, metastases.
• Magnesium deficiency: Impairs PTH secretion and action.

Symptoms (Driven by Hypocalcemia)

Neuromuscular

• Paresthesias (perioral, fingertips)
• Muscle cramps, tetany (Trousseau's sign: carpal spasm with BP cuff; Chvostek's sign: facial twitch on nerve tap)
• Seizures

Neuropsychiatric

• Fatigue, depression, anxiety, cognitive impairment, brain fog

Ectodermal

• Dry skin, brittle nails, hair loss, cataracts, dental enamel defects

Cardiac

• Prolonged QT interval, arrhythmias, heart failure

Diagnosis

• Low serum calcium, high phosphate
• Low or inappropriately normal PTH (key differentiator from pseudohypoparathyroidism, where PTH is high)
• Check Mg²⁺, 25-OH vitamin D, urinary calcium

Treatment

• Calcium carbonate/citrate: 1–3 g elemental calcium/day in divided doses.
• Active vitamin D (calcitriol): 0.25–2 µg/day to enhance intestinal absorption.
• PTH replacement (Natpara): For refractory cases; requires monitoring.
• Magnesium repletion if deficient.

Long-Term Monitoring

Essential for detecting nephrocalcinosis, renal function decline, and bone density changes. Patient education on symptom recognition (tetany, seizures) prevents emergencies.

Hypoparathyroidism is manageable but requires lifelong vigilance and partnership with an endocrinologist.