Chart — Renal
Kidney Stone Types Comparison
The four stone types lined up by the details that matter on exams: how common, the urine pH they favor, whether they show on x-ray, and how to prevent them.
Educational use only. Prevention is individualized and provider-directed. This chart is an educational comparison aid. This material supports nursing education and exam review. It is not medical advice and is not a substitute for clinical judgment, institutional policy, or medical direction. Always follow facility protocols and current provider orders.
Side by Side
| Stone type | Frequency | Urine pH | X-ray | Prevention |
|---|---|---|---|---|
| Calcium (oxalate/phosphate) | Most common (~75–80%) | Oxalate: any pH · phosphate: alkaline | Radiopaque (visible) | High fluids; limit oxalate & sodium; keep dietary calcium NORMAL |
| Struvite (infection) | ~10–15% | Alkaline | Radiopaque; can form staghorn | Treat/prevent UTIs; remove stone; acidify urine per orders |
| Uric acid | ~5–10% | Acidic | Radiolucent (NOT seen on plain x-ray) | Limit purines; alkalinize urine; allopurinol if gout; high fluids |
| Cystine | Rare (hereditary) | Acidic | Faintly radiopaque | High fluids; alkalinize urine; cystine-binding agents |
Exam Traps
- ✦Calcium = most common; struvite = infection stones in ALKALINE urine (staghorn); uric acid/cystine form in ACIDIC urine.
- ✦Uric acid stones are RADIOLUCENT — not seen on plain x-ray (use CT).
- ✦Calcium-oxalate prevention: keep dietary calcium NORMAL; limit oxalate (spinach/nuts/chocolate/tea) and sodium.
- ✦Uric acid: limit purines, alkalinize urine, allopurinol if gout.
- ✦High fluids to keep urine dilute prevents ALL stone types.
Related Resources
Standards & sources
Fact-checked Jun 21, 2026This page is written to align with KDIGO Clinical Practice Guidelines · National Kidney Foundation (NKF). It is an educational summary, not a citation of any single document — always verify specific doses, values, and protocols against current guidelines and your facility policy. How we source content →