🦴 Calcium / PTH Interpretation
PTH-based aetiology triage of hyper- and hypocalcaemia, the assessment sequence and the CKD-MBD pattern. Browser-side reference.
Correct for albumin or measure ionised calcium before acting.
Paste the link in Slack, Teams, X, or LinkedIn — the preview image comes from this page’s Open Graph card.
When to use
Confirm true calcium disturbance, then classify by whether PTH is appropriate — PTH is the watershed.
How it works
Core panel: calcium + phosphate + PTH (+ 25-OH-D, magnesium, creatinine). Confirm with corrected/ionised calcium first.
Key points
- Correct for albumin or measure ionised calcium before acting.
- Hypercalcaemia with PTH ↑: primary hyperparathyroidism, FHH, lithium.
- Hypercalcaemia with PTH ↓: malignancy, vitamin D toxicity, granulomatous disease.
- Correct low magnesium first in hypocalcaemia.
References
Worked calculation
The values below come from this tool's own example placeholders and are computed server-side with the formula shown on this page, so the arithmetic can be checked quickly. It demonstrates how to substitute values only — it is not clinical advice and not a real case.
| View | Assessment sequence |
|---|
→Key pointAssessment sequence
- Confirm first：Albumin-corrected calcium or ionised calcium (avoid spurious hypocalcaemia from low albumin; see 'Corrected calcium')
- Core panel：Calcium + phosphate + PTH (+ 25-OH-D, magnesium, creatinine)
- PTH is the watershed：For both high and low calcium, classify the cause by whether PTH is 'appropriate'
| View | CKD-MBD |
|---|
→Key pointCKD-MBD pattern
- Typical：High phosphate, low/normal calcium, 1,25-D ↓, secondary hyperparathyroidism (PTH ↑)
- Monitoring：Calcium, phosphate, PTH, 25-OH-D, ALP; for the calcium-phosphate product see that tool
Frequently asked questions
- What is Calcium / PTH Interpretation?
- PTH-based aetiology triage of hyper- and hypocalcaemia, the assessment sequence and the CKD-MBD pattern. Browser-side reference.
- How is Calcium / PTH Interpretation calculated? What is the core formula?
- Core panel: calcium + phosphate + PTH (+ 25-OH-D, magnesium, creatinine). Confirm with corrected/ionised calcium first.
- When is Calcium / PTH Interpretation used?
- Confirm true calcium disturbance, then classify by whether PTH is appropriate — PTH is the watershed.
- What are the key clinical points for Calcium / PTH Interpretation?
- Correct for albumin or measure ionised calcium before acting. Hypercalcaemia with PTH ↑: primary hyperparathyroidism, FHH, lithium. Hypercalcaemia with PTH ↓: malignancy, vitamin D toxicity, granulomatous disease. Correct low magnesium first in hypocalcaemia.
- What are the limits and cautions when using Calcium / PTH Interpretation?
- For licensed clinicians and clinical researchers. Interpret results with history, investigations and local protocols; not a diagnosis or prescription, and not a substitute for multidisciplinary decision-making or local guidelines.
- How is Calcium / PTH Interpretation calculated in practice? Can you show a worked example?
- Inputs: View Assessment sequence → Result: Key point Assessment sequence（Confirm first: Albumin-corrected calcium or ionised calcium (avoid spurious hypocalcaemia from low albumin; see 'Corrected calcium'), Core panel: Calcium + phosphate + PTH (+ 25-OH-D, magnesium, creatinine), PTH is the watershed: For both high and low calcium, classify the cause by whether PTH is 'appropriate'） Inputs: View CKD-MBD → Result: Key point CKD-MBD pattern（Typical: High phosphate, low/normal calcium, 1,25-D ↓, secondary hyperparathyroidism (PTH ↑), Monitoring: Calcium, phosphate, PTH, 25-OH-D, ALP; for the calcium-phosphate product see that tool）