Calcium Stones
Calcium stones are the disease behind "stone disease" — by far the most common, and driven by a handful of correctable metabolic abnormalities in the urine.
The big picture
Calcium stones are the disease behind "stone disease" — they are by far the most common stones, and unlike infection or uric acid stones they are driven by a handful of metabolic abnormalities in the urine that you can identify and correct. That is the whole point of working a calcium-stone former up: the stone in front of you is a symptom, and the 24-hour urine tells you which metabolic lever to pull so the next one doesn't form.
The framework: calcium stones are mostly calcium oxalate (some calcium phosphate); their formation is driven by named metabolic abnormalities — hypercalciuria, hyperoxaluria, hyperuricosuria, hypocitraturia — and each has a targeted treatment.
Mechanism pathway
Tap any step to see why it happens.
Diagnostic algorithm
Each step answers one question. Tap to expand.
Board traps
Calcium oxalate is the most common stone; calcium stones are radio-opaque.
Work up every recurrent calcium stone former with a 24-hour urine — the abnormality directs therapy.
Don't restrict dietary calcium — it worsens oxalate absorption; restrict sodium and use a thiazide instead.
Hypercalciuria has three types — absorptive (gut), renal (leak), resorptive (bone/PTH).
Calcium stones + hypercalcaemia → primary hyperparathyroidism (parathyroidectomy is curative).
Hypocitraturia → potassium citrate; hyperuricosuria → allopurinol.