🦴 Calcium / PTH Interpretation
UseConfirm true calcium disturbance, then classify by whether PTH is appropriate — PTH is the watershed.
SourceStandard approach to calcium disorders and PTH interpretation
This-shift next steps
After scoring: open the scene pack, peer scores, and the matching pathway. Local reference — no HIS write.
Paste the link in Slack, Teams, X, or LinkedIn — the preview image comes from this page’s Open Graph card.
Methodology · worked example, guidelines & full notes
Correct for albumin or measure ionised calcium before acting.
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 | Hypercalcaemia |
|---|
→Key pointHypercalcaemia
- PTH ↑ or inappropriately normal：Primary hyperparathyroidism, tertiary hyperparathyroidism, familial hypocalciuric hypercalcaemia (FHH, check urine calcium), lithium
- PTH ↓ (suppressed)：Malignancy (PTHrP/bone metastasis/haematological), vitamin D toxicity, granulomatous (1,25-D ↑), hyperthyroidism, immobilisation
- Next step：If PTH ↓, check PTHrP, 25-OH-D, 1,25-D, protein electrophoresis; management see 'Hypercalcaemia management'
| 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'
Verification & sources · governance
FAQ
Frequently asked questions
- 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.
- Does Calcium / PTH Interpretation upload patient data? Where is it calculated?
- Calculation runs locally in the browser; inputs and results are not uploaded. For licensed clinicians only; interpret with history, investigations and local protocols — not a diagnosis or prescription.
- How is Calcium / PTH Interpretation calculated in practice? Can you show a worked example?
- Inputs: View Hypercalcaemia → Result: Key point Hypercalcaemia（PTH ↑ or inappropriately normal: Primary hyperparathyroidism, tertiary hyperparathyroidism, familial hypocalciuric hypercalcaemia (FHH, check urine calcium), lithium, PTH ↓ (suppressed): Malignancy (PTHrP/bone metastasis/haematological), vitamin D toxicity, granulomatous (1,25-D ↑), hyperthyroidism, immobilisation, Next step: If PTH ↓, check PTHrP, 25-OH-D, 1,25-D, protein electrophoresis; management see 'Hypercalcaemia management'） 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'）