159. Kidney stone disease - etiology, pathogenesis, clinical manifestations, complications.

Kidney Stone Disease (Nephrolithiasis)

✅ Definition

Kidney stone disease refers to the formation of solid crystalline structures (calculi) within the renal calyces, pelvis, or ureter due to supersaturation of urine with stone-forming substances.

✅ Etiology

✅ Pathogenesis

1. Supersaturation of urine with stone-forming solutes (Ca²⁺, oxalate, urate, cystine).
2. Crystallization: When solute concentration exceeds solubility → nucleation of crystals.
3. Crystal aggregation and retention in renal tubules or collecting system.
4. Lack of inhibitors like citrate, magnesium, and Tamm-Horsfall protein enhances stone growth.
5. In struvite stones, infection by urease-positive organisms leads to alkaline urine → magnesium-ammonium-phosphate crystal formation.

✅ Types of Stones (High-Yield)

✅ Clinical Manifestations

• Renal colic: Sudden, severe flank pain radiating to groin/testicles/labia.
• Hematuria (gross or microscopic).
• Nausea and vomiting (visceral pain reflex).
• Dysuria or frequency (if stone near bladder).
• Obstruction symptoms if stone lodges in ureter.
• Infection signs: fever, chills if superimposed UTI.

✅ Complications

✅ Summary Table

Let me know if you'd like a visual stone type summary, urine pH and stone association table, or mnemonics for stone types!

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