Hypercalcaemia

🔍 When to Suspect

Non-specific symptoms summarised as "bones (pain), stones (renal), groans (abdominal pain, constipation), and psychiatric overtones (fatigue, confusion, depression)"; also consider with polydipsia and polyuria

From the full topic in The Ocean Library: Hypercalcaemia

🧭 When to suspect

Hypercalcaemia is an albumin-adjusted (corrected) serum calcium above the upper reference limit – typically > 2.60 mmol/L, though local laboratory ranges vary. It is common, and over 90% of cases are explained by just two conditions: primary hyperparathyroidism (PHPT) – usually mild, often incidental, in an otherwise well outpatient – and malignancy – typically a sicker patient with a higher calcium. The classic syndrome is “stones, bones, abdominal moans and psychic groans”: renal stones, bone pain, abdominal pain with constipation and nausea, thirst and polyuria, and cognitive change. In practice, the commonest presentation is now an incidental finding on a routine biochemical screen.

Two questions drive everything: how high and how unwell the patient is (severity sets urgency), and what the parathyroid hormone (PTH) is doing (PTH points to the cause).

Adjusted calcium	Severity	Action
2.20–2.60 mmol/L	Normal	Within reference range (local labs vary) – no action
2.60–3.00 mmol/L	Mild	Often asymptomatic; confirm, review medication, measure PTH – usually a primary-care work-up
3.00–3.50 mmol/L	Moderate	Prompt treatment usually needed; same-day admission if symptomatic or dehydrated
> 3.50 mmol/L	Severe	Emergency – risk of dysrhythmia and coma; same-day admission for IV rehydration

Beyond PHPT and malignancy (myeloma, breast, lung – especially squamous, renal), consider drugs (thiazide diuretics, lithium, calcium and vitamin D supplements, vitamin A), granulomatous disease (sarcoidosis, tuberculosis), thyrotoxicosis, prolonged immobilisation, adrenal insufficiency, milk-alkali syndrome, and familial hypocalciuric hypercalcaemia (FHH).

Source: Society for Endocrinology · NICE NG132

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