What are the signs and physical exam findings for patients with suspected kidney stones?

Signs and Physical Examination Findings for Kidney Stones

Patients with suspected kidney stones require a thorough physical examination with specific attention to detecting flank tenderness, abdominal masses, fever, and signs of systemic complications, though the physical exam is often unremarkable in uncomplicated cases. 1

Key Clinical Presentations

Primary Symptoms

• Renal colic - the classic presentation with severe, colicky flank pain radiating to the groin 2
• Hematuria - either gross or microscopic, present in most cases 1, 2
• Dysuria and urinary frequency - common accompanying urinary symptoms 2
• Nausea and vomiting - frequently associated with acute stone episodes 3
• Fever - suggests concurrent infection or pyelonephritis, requiring urgent intervention 1, 4

Physical Examination Components

Focused examination should include:

• Costovertebral angle (CVA) tenderness - assess for flank pain and tenderness on percussion 1
• Abdominal examination - palpate for masses, tenderness, and peritoneal signs 1, 5
• Vital signs assessment - fever (temperature >38°C) indicates possible infection requiring immediate evaluation 1, 4
• Supraclavicular lymph node examination - to exclude other pathology 1
• Lower extremity edema assessment - may indicate urinary obstruction or other complications 1
• Varicocele examination - unilateral varicocele may suggest venous obstruction from renal pathology 1
• Subcutaneous nodules - rare but may indicate systemic disease 1

Critical Red Flags on Physical Exam

Immediate evaluation is mandatory for: 1

• Fever with flank pain - suggests infected obstructing stone or pyelonephritis, requiring urgent urologic intervention 1, 4
• Signs of sepsis - tachycardia, hypotension, altered mental status 1
• Solitary kidney patients - any stone presentation requires emergent assessment 1
• Anuria or oliguria - suggests bilateral obstruction or obstruction in solitary kidney 1

Important Clinical Pearls

The physical examination in uncomplicated kidney stones is often surprisingly benign despite severe symptoms. 1 Many patients with confirmed urolithiasis have minimal physical findings beyond CVA tenderness. 3

Colicky abdominal pain in children should always prompt thorough evaluation for urolithiasis, as symptoms may be subtle or misleading in pediatric populations. 5 General abdominal manifestations can be the first presentation of renal stones in children. 5

Lower back pain without hematuria on urinalysis should prompt consideration of musculoskeletal causes rather than kidney stones. 4 The absence of microscopic hematuria significantly reduces the likelihood of urolithiasis. 4

Essential Diagnostic Workup Accompanying Physical Exam

Every patient requires: 1, 4

• Urinalysis with dipstick and microscopy - assess for hematuria, pH, crystalluria, leukocyte esterase, nitrites, and WBCs 1, 4
• Blood tests - creatinine, uric acid, ionized calcium, sodium, potassium, CBC, and CRP 1, 4
• Urine culture if infection suspected - based on urinalysis findings or clinical presentation 1

Ultrasound is the primary first-line imaging modality and should not delay emergency care, with 45% sensitivity for ureteral stones and 94% specificity. 1 Non-contrast CT remains the gold standard after ultrasound for acute flank pain, with sensitivity and specificity exceeding 95%. 1