Which specialist should a patient with kidney stones be referred to?

Specialist Referral for Kidney Stones

Patients with kidney stones should be referred to a urologist for surgical management and procedural interventions, while nephrology referral is indicated for recurrent or extensive nephrolithiasis, metabolic evaluation, and when chronic kidney disease complicates stone disease. 1, 2

Urology Referral

Urologists are the primary specialists for kidney stone management, as they perform the definitive procedural interventions including extracorporeal shock wave lithotripsy (ESWL), ureteroscopy (URS), and percutaneous nephrolithotomy (PCNL). 1

Immediate Urology Referral Indications:

• Stones requiring active removal: stones >10 mm, urinary obstruction with infection, or refractory pain despite medical management 1, 3
• Surgical intervention planning: when conservative management fails after 14 days of observation or medical expulsive therapy 3
• Complex stone burden: large renal stones requiring PCNL or multiple stones requiring comprehensive surgical planning 1
• Anatomic complications: hydronephrosis, steinstrasse formation, or anatomic abnormalities complicating stone passage 1

Urology Manages:

• Procedural stone removal: ESWL for stones in ureter/kidney, ureteroscopy with laser lithotripsy, PCNL for large renal stones, and ureteral stent placement 1, 4
• Acute stone episodes: medical expulsive therapy with alpha-blockers for distal ureteral stones ≤10 mm 1
• Follow-up imaging: monitoring stone position and assessing for complications within 14 days of conservative management 3

Nephrology Referral

Nephrology consultation is specifically indicated for recurrent or extensive nephrolithiasis as stated in major kidney disease guidelines. 1, 2

Nephrology Referral Indications:

• Recurrent nephrolithiasis: multiple stone episodes requiring metabolic evaluation and medical prevention strategies 1, 2
• Extensive stone burden: bilateral stones, multiple stones, or hereditary stone disease (cystinuria, primary hyperoxaluria) 1, 2
• Metabolic complications: persistent electrolyte abnormalities (particularly potassium), refractory hypertension requiring ≥4 antihypertensive agents 1, 2
• CKD with stones: eGFR <30 mL/min/1.73 m² or significant proteinuria (ACR ≥300 mg/g) complicating stone disease 1, 2
• High-risk metabolic features: family history of stones, single kidney, malabsorption/intestinal disease, or young age at first stone (<30 years) 4, 3

Nephrology Manages:

• Comprehensive metabolic evaluation: 24-hour urine collection analyzing calcium, oxalate, citrate, uric acid, sodium, and volume 1
• Medical stone prevention: thiazide diuretics for hypercalciuria, potassium citrate for hypocitraturia, allopurinol for hyperuricosuria 1, 3
• Dietary counseling: sodium restriction (≤2,300 mg/day), appropriate calcium intake (1,000-1,200 mg/day from food), protein moderation, and fluid optimization (≥2-3 L/day) 1
• Specialized stone management: oral chemolysis for uric acid stones with alkalinization therapy (pH 7.0-7.2), cystine stone management with high fluid intake (≥4 L/day) and sodium/protein restriction 1

Co-Management Approach

For patients with both active stones and recurrent disease, coordinated care between urology and nephrology optimizes outcomes. 1, 2

Multidisciplinary Care Should Include:

• Urologist: leads acute stone management and surgical interventions 1
• Nephrologist: provides metabolic evaluation and long-term prevention strategies for recurrent stones 1, 2
• Dietitian: delivers specialized dietary counseling for stone prevention (oxalate restriction, calcium timing with meals, sodium reduction) 1

Common Pitfalls to Avoid

• Do not delay urology referral for stones >10 mm or those causing obstruction with infection, as these require urgent intervention 1, 3
• Do not overlook nephrology referral in patients with recurrent stones (≥2 episodes), as metabolic evaluation can reduce recurrence rates by >50% with targeted therapy 1, 3
• Do not assume all stone patients need nephrology: single uncomplicated calcium oxalate stones <10 mm that pass spontaneously can be managed by primary care with conservative measures (hydration, dietary modification) 3
• Recognize hereditary patterns: patients ≤46 years with stones, bilateral/multifocal stones, or family history suggesting hereditary syndromes require genetic counseling and nephrology evaluation 1
• Avoid calcium restriction: contrary to intuition, dietary calcium restriction increases stone risk; maintain 1,000-1,200 mg/day from food sources 1