Primary hyperparathyroidism vs Secondary and tertiary hyperparathyroidism
How to tell Primary hyperparathyroidism and Secondary and tertiary hyperparathyroidism apart when a board question makes them look alike.
Primary is PTH-high calcium-high without CKD trigger; secondary is PTH-high because calcium is low/normal; tertiary is autonomous PTH-high calcium-high after chronic CKD.
Side by side
Autonomous parathyroid hormone secretion, usually adenoma, causing high calcium, low phosphate, kidney stones, bone pain, abdominal symptoms, and psychiatric symptoms.
Secondary hyperparathyroidism is compensatory PTH rise from chronic kidney disease or vitamin D deficiency; tertiary is autonomous PTH after long-standing secondary disease with hypercalcemia.
Parathyroid tissue secretes PTH without appropriate calcium feedback, increasing bone resorption, renal calcium reabsorption, phosphate wasting, and vitamin D activation.
Low calcium, phosphate retention, or low vitamin D chronically stimulates parathyroid hyperplasia; prolonged stimulation can become autonomous in tertiary disease.
High PTH with high calcium and low phosphate, often with parathyroid adenoma, supports primary hyperparathyroidism.
Secondary has high PTH with low or normal calcium; CKD often raises phosphate. Tertiary has high PTH and high calcium after chronic kidney disease.
The trap
PTH is high in all three, so calcium level and kidney disease history decide the type.
Watch it explained
Test it nowThe repair move
For high PTH, immediately pair it with calcium level and chronic kidney disease history.
Try a free question
CoreA patient has nephrolithiasis, constipation, bone pain, high serum calcium, low phosphate, and elevated PTH. Imaging localizes a parathyroid adenoma. Which diagnosis is most likely?
Show answer and explanation
Answer: A. Primary hyperparathyroidism. High calcium with elevated PTH from a parathyroid adenoma supports primary hyperparathyroidism.
Why the other choices are tempting
- B. Secondary hyperparathyroidism is compensatory and usually has low or normal calcium.
- C. Tertiary hyperparathyroidism follows long-standing secondary disease, usually CKD.
- D. Hypoparathyroidism has low PTH and low calcium.
- E. Pseudohypoparathyroidism has PTH resistance with low calcium and high PTH.
Flashcards
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What lab pattern points to primary hyperparathyroidism?
High calcium with elevated PTH and often low phosphate points to primary hyperparathyroidism.
What lab pattern points to secondary hyperparathyroidism from CKD?
High PTH with low or normal calcium and high phosphate in CKD points to secondary hyperparathyroidism.
Quick answers
What is the fastest way to tell Primary hyperparathyroidism from Secondary and tertiary hyperparathyroidism?
Primary is PTH-high calcium-high without CKD trigger; secondary is PTH-high because calcium is low/normal; tertiary is autonomous PTH-high calcium-high after chronic CKD.
What is the key clue for Primary hyperparathyroidism?
Autonomous parathyroid hormone secretion, usually adenoma, causing high calcium, low phosphate, kidney stones, bone pain, abdominal symptoms, and psychiatric symptoms.
What is the key clue for Secondary and tertiary hyperparathyroidism?
Secondary hyperparathyroidism is compensatory PTH rise from chronic kidney disease or vitamin D deficiency; tertiary is autonomous PTH after long-standing secondary disease with hypercalcemia.
What is the common trap with Primary hyperparathyroidism vs Secondary and tertiary hyperparathyroidism?
PTH is high in all three, so calcium level and kidney disease history decide the type.