⚠️ Hypercalcaemia = Albumin-adjusted Ca²⁺ > 2.6 mmol/L (UK) / > 10.5 mg/dL (US). 👉 >90% of cases due to malignancy or primary hyperparathyroidism.

🧪 Hypercalcaemia — Ward Quick Guide

🚑 Initial Management
💧 Hydration Oral fluids 3–4 L/day if mild (Ca²⁺ < 3.0 mmol/L) IV 0.9% saline 4–6 L/24 h if moderate–severe (watch for overload) Restrict to 2–3 L/day if 💔 heart failure risk Add loop diuretic (furosemide) only if fluid overloaded 🔍 Investigations Serum Ca²⁺ (corrected), phosphate, ALP, U&Es, PTH, vitamin D CXR (lung Ca / sarcoid), ESR/CRP Serum & urine paraproteins (myeloma) 💊 Drugs Bisphosphonate: Zoledronate 4 mg IV (≈15 min) or Pamidronate 60–90 mg IV (2–5 h) ↳ Onset 24–48 h, peak 4–7 days Steroids: Prednisolone 40–60 mg OD if sarcoid/lymphoma/granulomatous disease Calcitonin: 100 units SC/IM every 6–8 h for rapid short-term Ca²⁺ reduction Denosumab if bisphosphonate-refractory or significant renal impairment ⏱ Monitoring Daily Ca²⁺, U&Es, fluid balance ECG for arrhythmias (short QT, block, VT) 🛑 Refractory / Severe Dialysis if life-threatening hypercalcaemia with renal/cardiac failure 📌 Treat Underlying Cause Malignancy (oncology input) Primary hyperparathyroidism (consider surgery) Vitamin D excess, immobilisation, granulomatous disease

🚑 Initial Management

💧 Hydration
- Oral fluids 3–4 L/day if mild (Ca²⁺ < 3.0 mmol/L)
- IV 0.9% saline 4–6 L/24 h if moderate–severe (watch for overload)
- Restrict to 2–3 L/day if 💔 heart failure risk
- Add loop diuretic (furosemide) only if fluid overloaded
🔍 Investigations
- Serum Ca²⁺ (corrected), phosphate, ALP, U&Es, PTH, vitamin D
- CXR (lung Ca / sarcoid), ESR/CRP
- Serum & urine paraproteins (myeloma)
💊 Drugs
- Bisphosphonate: Zoledronate 4 mg IV (≈15 min) or Pamidronate 60–90 mg IV (2–5 h)
  ↳ Onset 24–48 h, peak 4–7 days
- Steroids: Prednisolone 40–60 mg OD if sarcoid/lymphoma/granulomatous disease
- Calcitonin: 100 units SC/IM every 6–8 h for rapid short-term Ca²⁺ reduction
- Denosumab if bisphosphonate-refractory or significant renal impairment
⏱ Monitoring
- Daily Ca²⁺, U&Es, fluid balance
- ECG for arrhythmias (short QT, block, VT)
🛑 Refractory / Severe
- Dialysis if life-threatening hypercalcaemia with renal/cardiac failure
📌 Treat Underlying Cause
- Malignancy (oncology input)
- Primary hyperparathyroidism (consider surgery)
- Vitamin D excess, immobilisation, granulomatous disease

📏 Calcium Conversion

State	US (mg/dL)	UK (mmol/L)
Normal	8.5–10.5	2.12–2.62
Hypocalcaemia	< 8.5	< 2.12
Hypercalcaemia	> 10.5	> 2.62

✅ Tip (UK practice): give IV bisphosphonate early once volume status is safe; re-check Ca²⁺ at 24–48 h to gauge response.

Conversion: mg/dL × 0.25 = mmol/L

🩸 Causes of Hypercalcaemia

Cause	Features / Management
🦴 Primary Hyperparathyroidism	Bone pain, stones, constipation, mood changes. Labs: ↑ Ca²⁺, ↑/normal PTH, ↓ phosphate. Tx: Parathyroidectomy, hydration, bisphosphonates.
🎗️ Malignancy	Advanced cancer, weight loss, confusion. Labs: ↑ Ca²⁺, ↓ PTH, ↑ PTHrP. Tx: IV fluids, bisphosphonates, denosumab, treat tumour.
🌞 Vitamin D Excess	GI upset, dehydration. Labs: ↑ Ca²⁺, ↑ Vit D, ↓ PTH. Tx: Stop Vit D, fluids, steroids, bisphosphonates.
🫁 Sarcoidosis	Fatigue, polyuria, respiratory disease. Labs: ↑ Ca²⁺, ↑ 1,25 Vit D. Tx: Steroids + hydration.
💊 Thiazides	Mild, asymptomatic. Labs: ↑ Ca²⁺, ↓ PTH. Tx: Stop drug, monitor.
👨‍👩‍👧 Familial Hypocalciuric Hypercalcaemia (FHH)	Mild, lifelong, benign. Labs: ↑ Ca²⁺, ↓ urine Ca²⁺. Tx: None required.
🛏️ Immobilisation	High bone turnover states (Paget’s). Tx: Mobilisation, bisphosphonates.
🔥 Hyperthyroidism	Mild hypercalcaemia with thyrotoxic features. Tx: Treat thyroid disease.

🧾 Clinical Features – “Bones, Stones, Groans, Moans”

🦴 Bones: pain, fractures, myeloma
💎 Stones: renal calculi, polyuria, polydipsia
🤢 Groans: constipation, abdominal pain, pancreatitis
😵 Moans: confusion, depression, psychosis, coma
Other: hypotonia, hypertension, band keratopathy 👁️

🔍 Investigations

🧪 FBC (anaemia in myeloma/malignancy)
U&E: dehydration, renal failure
ESR ↑ (myeloma, cancer)
📉 ECG: Short QT
🫁 CXR: SCC lung, sarcoidosis
PTH: ↑ in primary hyperparathyroidism, ↓ in malignancy
Urinary Ca²⁺ low in FHH
Special tests: PTHrP, bone scan, Vit D, ACE (sarcoid)

💊 Definitive Management

💧 IV fluids (mainstay)
💊 Loop diuretics (after rehydration)
💉 Bisphosphonates (Zoledronate, Pamidronate)
🌿 Steroids (sarcoid, lymphoma)
🧪 Calcitonin or dialysis if refractory

📚 Reference

Hypercalcaemia Guideline for Primary Care

🧑‍⚕️ Case Examples — Hypercalcaemia

Case 1 (Primary Hyperparathyroidism): 🦴 A 62-year-old woman presents with fatigue, constipation, bone pain, and recurrent renal stones. Bloods: calcium 3.0 mmol/L, PTH inappropriately elevated, low phosphate. Analysis: Classic “bones, stones, abdominal groans, psychiatric overtones.” Commonest outpatient cause of hypercalcaemia. Diagnosis: Primary hyperparathyroidism due to parathyroid adenoma. Management: Definitive = parathyroidectomy (if symptomatic or criteria met). Interim = hydration, avoid thiazides/lithium, monitor bone density and renal function.
Case 2 (Malignancy-Associated Hypercalcaemia): 🎗️ A 70-year-old man with lung cancer presents with confusion, dehydration, and constipation. Calcium 3.5 mmol/L, suppressed PTH, raised PTHrP. Analysis: Malignancy is the most common inpatient cause of severe hypercalcaemia, due to humoral (PTHrP) or osteolytic metastases. Diagnosis: Hypercalcaemia of malignancy. Management: IV fluids (saline rehydration), IV bisphosphonate (zoledronic acid), oncology input. Prognosis usually poor.
Case 3 (Vitamin D Intoxication): 💊 A 55-year-old man on over-the-counter supplements presents with nausea, abdominal pain, and muscle weakness. Calcium 3.2 mmol/L, suppressed PTH, high 25-hydroxyvitamin D. Analysis: Excessive vitamin D → ↑ intestinal calcium absorption and bone resorption. Diagnosis: Vitamin D toxicity–induced hypercalcaemia. Management: Stop vitamin D, IV fluids, bisphosphonates if needed, steroids in refractory cases.

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Hypercalcaemia