To whom should a patient with elevated Parathyroid Hormone (PTH) intact lab levels be referred?

Referral for Elevated PTH Intact Lab Levels

Patients with elevated intact parathyroid hormone (PTH) levels should be referred to an endocrinologist for comprehensive evaluation and management, with consideration for surgical referral to a parathyroid surgeon if primary hyperparathyroidism is confirmed. 1

Initial Evaluation and Referral Algorithm

Step 1: Determine the Type of Hyperparathyroidism

• Primary Hyperparathyroidism

  • Elevated PTH with hypercalcemia → Refer to endocrinologist
  • If imaging localizes a parathyroid adenoma → Subsequent referral to parathyroid surgeon

• Secondary Hyperparathyroidism

  • Elevated PTH with normal/low calcium and underlying cause (typically CKD)
  • For CKD patients:
    • GFR < 45 mL/min/1.73m² → Refer to nephrologist 2
    • Severe and progressive hyperparathyroidism despite medical management → Consider endocrinology consultation

Step 2: Urgency of Referral Based on PTH Level

• Severely Elevated PTH (>800 pg/mL)

  • Urgent referral to endocrinology and surgical evaluation 1
  • Higher risk of bone disease, fractures, and calciphylaxis

• Moderately Elevated PTH (300-800 pg/mL)

  • Prompt referral to endocrinology
  • Timing depends on calcium levels and symptoms

• Mildly Elevated PTH

  • Routine referral to endocrinology
  • Rule out secondary causes (vitamin D deficiency, renal insufficiency)

Special Considerations

For CKD Patients

• For CKD G3a-G5 not on dialysis: Refer to nephrologist for evaluation of modifiable factors (hyperphosphatemia, hypocalcemia, vitamin D deficiency) 2
• For CKD G5D (dialysis patients): Managed primarily by nephrologist with potential referral to endocrinology for refractory cases 2
• If PTH levels persistently exceed 800 pg/mL despite medical therapy → Consider referral to parathyroid surgeon for parathyroidectomy evaluation 1

For Symptomatic Patients

• Patients with bone pain, kidney stones, fragility fractures, or significant bone mineral density reduction should receive expedited referral to endocrinology 1
• Younger patients with hyperparathyroidism tend to be more symptomatic (77.8% vs 39.1%) and may need more urgent evaluation 3

For Unusual Presentations

• Hypercalcemia with normal or undetectable PTH levels still requires endocrinology referral as rare cases of primary hyperparathyroidism can present this way 3, 4

Pitfalls to Avoid

1. Delayed referral - Untreated hyperparathyroidism can lead to progressive bone disease, kidney stones, and increased fracture risk

2. Missing secondary causes - Always evaluate for vitamin D deficiency, renal insufficiency, and medications that can affect calcium/PTH before specialist referral

3. Overlooking normocalcemic hyperparathyroidism - Some patients with primary hyperparathyroidism may have normal calcium levels but elevated PTH, still requiring endocrinology evaluation

4. Focusing only on PTH levels - The clinical picture, including calcium levels, phosphate levels, vitamin D status, and kidney function, should guide referral decisions

5. Neglecting monitoring - While awaiting specialist evaluation, patients should have regular monitoring of calcium, phosphate, and PTH levels every 3-6 months 1

By following this referral algorithm, patients with elevated PTH levels will receive appropriate specialist care to minimize complications and improve outcomes related to bone health, kidney function, and overall quality of life.