Can a patient have a kidney stone without presenting with hematuria (blood in the urine)?

Kidney Stones Can Occur Without Hematuria

Yes, patients can have kidney stones without presenting with hematuria (blood in the urine). While hematuria is a common finding in patients with urolithiasis, its absence does not rule out the presence of kidney stones.

Epidemiology and Evidence

• According to the American College of Radiology (ACR) Appropriateness Criteria, "a number of pediatric patients with urolithiasis do not have hematuria" 1
• Studies show approximately 6% of patients with symptomatic urinary stones confirmed by CT imaging have no microhematuria 2
• In a large study of 950 patients with suspected renal colic, 16% (95 patients) had confirmed kidney stones on CT but no hematuria on microscopic urinalysis 3

Factors Associated with Absence of Hematuria in Stone Patients

• Lower stone location (distal ureter to bladder) is more likely to present without hematuria (odds ratio 2.72) 2
• Presence of perinephric stranding on CT imaging (odds ratio 1.87) 2
• Elevated blood urea nitrogen (BUN) levels (odds ratio 1.06) 2

Diagnostic Implications

• Hematuria testing alone has limited utility for diagnosing kidney stones:

  • Sensitivity of 84% (meaning 16% of stone cases will be missed if relying solely on hematuria) 3
  • Specificity of only 48% (many patients without stones will have hematuria) 3
  • Negative predictive value of 65% (absence of hematuria does not reliably exclude stones) 3

• The absence of hematuria should not deter further evaluation when kidney stones are clinically suspected 1, 3

Imaging Recommendations

• For patients with suspected kidney stones but no hematuria:
  • Renal ultrasonography is recommended as first-line imaging, particularly in pregnant patients 4
  • Non-contrast CT is the gold standard diagnostic tool with sensitivity and specificity well above 90% 1
  • CT is particularly useful when there is high clinical suspicion despite negative ultrasound findings 1

Clinical Pearls and Pitfalls

• Key pitfall: Relying on the presence of hematuria to rule in or rule out kidney stones can lead to missed diagnoses 3
• Important consideration: The classic triad of flank pain, hematuria, and nausea/vomiting may not be present in all cases of urolithiasis 2
• Clinical pearl: In patients with typical renal colic symptoms but negative hematuria, proceed with appropriate imaging rather than dismissing the possibility of kidney stones 1, 3

Conclusion for Clinical Practice

When evaluating patients with symptoms suggestive of kidney stones (such as flank pain or renal colic), clinicians should not use the absence of hematuria to exclude the diagnosis of urolithiasis. Appropriate imaging should be pursued based on clinical presentation regardless of urinalysis findings 1, 3.