Hyperparathyroidism is excessive secretion of parathyroid hormone (PTH) by the parathyroid glands, leading to hypercalcemia and hypophosphatemia.
Classification
- Primary: Autonomous gland overactivity (adenoma 85%, hyperplasia 15%, carcinoma <1%).
- Secondary: Compensatory PTH rise due to chronic hypocalcemia (CKD, vitamin D deficiency, malabsorption).
- Tertiary: Autonomous hyperfunction after long‑standing secondary HPT (usually in end‑stage renal disease).
Clinical Manifestations
- “Bones, stones, groans, and psychiatric overtones”:
- Bones: Osteopenia, fractures, bone pain.
- Stones: Nephrolithiasis, nephrocalcinosis.
- Groans: Abdominal pain (pancreatitis, peptic ulcer), constipation.
- Psychiatric: Depression, anxiety, cognitive changes.
- Fatigue, weakness, polyuria/polydipsia, hypertension.
Diagnosis
- Elevated serum calcium + inappropriately normal/high PTH.
- 25‑OH vitamin D, 24‑hr urine calcium, renal function, bone density (DXA).
- Imaging (sestamibi scan, US, 4D‑CT) for surgical localization in primary HPT.
Treatment
- Primary: Parathyroidectomy (curative). Cinacalcet if surgery contraindicated.
- Secondary: Treat underlying cause (vitamin D, phosphate binders, calcimimetics in CKD).
- Tertiary: Often requires subtotal/total parathyroidectomy with autotransplantation.
