Renal Stones
Clinical features: Often referred to as "painful bones, renal stones, abdominal groans, psychic moans." However, most patients are asymptomatic and it is found incidentally on routine biochemistry.
What our notes say
- Clinical features: Often referred to as "painful bones, renal stones, abdominal groans, psychic moans." However, most patients are asymptomatic and it is found incidentally on routine biochemistry. (Endocrine & Renal Pathology — Must Know Notes)
- A 32-year-old man has a renal stone 3 years after laparotomy and ileal resection for Crohn's disease. (Junior Clerkship in Internal Medicine (MBIM4100) main exam, Paper One: 31 Januar)
- (c) Renal stones and nephrocalcinosis, polyuria and nephrogenic diabetes insipidus, constipation and peptic ulcer, pancreatitis, bone pain or fractures, arrhythmias (short QT) and confusion. (Chemical Pathology Practice Examination)
- Name the 4 types of renal stones in order of frequency. (Exam Prep: Skin Infections, Psoriasis & Pemphigus)
- | Crystalluria | Maintain adequate fluid intake to prevent renal stone formation | (Pharmco Notes)
- Toxicity: Hypercalcemia, hypercalciuria, renal stones, soft tissue calcification (Chemical Pathology Practice Examination)
Practice questions on Renal Stones
Struvite renal stones are associated with
- Hyperuricemia
- Urease-producing bacterial infections
- Cystinuria
- Hypercalciuria
Answer: B. Urease-producing organisms (Proteus, Klebsiella) hydrolyze urea to ammonia, alkalinizing urine and precipitating magnesium ammonium phosphate (struvite). ---
The most common type of renal stone is
- Struvite (magnesium ammonium phosphate)
- Cystine
- Uric acid
- Calcium oxalate
Answer: D. Calcium oxalate stones are the most common (70–80%). Causes: hypercalciuria (idiopathic), hyperoxaluria. Uric acid stones (5–10%) associated with gout/hyperuricemia, acidic urine. Struvite stones (10–15%) associated with UTI by urease-producing bacteria (Proteus, Klebsiella), staghorn calculi. Cystine stones (1–2%) due to inherited defect in amino acid transport.
Struvite (triple phosphate) renal stones are associated with ---
- Hyperuricemia
- Urease-producing bacterial infections
- Cystinuria
- Hypercalciuria
Answer: B.