When should you order a urinalysis (urine analysis)?

When to Order Urinalysis

Urinalysis should be ordered for patients with symptoms suggestive of urinary tract infection, suspected renal disease, or specific risk factors, but should not be performed for asymptomatic individuals without clinical indications. 1, 2

Symptomatic Patients

Urinary Tract Infection Symptoms

• Order urinalysis when patients present with:
  • Dysuria (painful urination)
  • Frequency
  • Urgency
  • New or worsening urinary incontinence
  • Gross hematuria
  • Suprapubic pain
  • Flank pain (suggests pyelonephritis)
  • Fever with suspected urinary source 1, 2

Special Populations

• Long-term care facility residents:
  • Only test those with acute onset of UTI symptoms
  • Avoid testing asymptomatic residents 1
• Catheterized patients:
  • For suspected infection, obtain specimen after changing the catheter and allowing urine accumulation
  • Do not collect from extension tubing or collection bag 1

Screening Indications

• Microscopic hematuria evaluation
• Proteinuria assessment
• Suspected glomerular disease (especially with red cell casts or dysmorphic RBCs)
• Overactive bladder evaluation 1
• Screening for asymptomatic bacteriuria in:
  • Pregnant women
  • Prior to urologic procedures with anticipated urothelial disruption 1, 3

Non-Indications (When NOT to Order)

• Asymptomatic individuals 1
• Routine screening in general population 3
• Surveillance cultures in asymptomatic neurogenic lower urinary tract dysfunction patients 1
• Follow-up testing after successful treatment (unless symptoms persist) 2

Components of Urinalysis

Basic Urinalysis

• Dipstick: leukocyte esterase, nitrites, blood, protein, pH, specific gravity
• Microscopic examination: WBCs, RBCs, bacteria, casts, crystals 2, 4

Additional Testing

• Urine culture (with susceptibility testing) should be ordered when:
  • Pyuria (≥10 WBCs/high-power field) or positive leukocyte esterase/nitrite is present
  • Patient has risk factors for complicated UTI
  • Suspected urosepsis (paired with blood cultures)
  • Recurrent UTIs 1, 2, 5

Interpretation Pitfalls

• False positives for infection:

  • Contaminated specimens (multiple organisms)
  • Asymptomatic bacteriuria (common in elderly, catheterized patients)
  • Pyuria without infection (common in older adults with lower urinary tract symptoms) 2, 5

• False negatives:

  • Dilute urine
  • Recent antibiotic use
  • Non-nitrite producing organisms 4, 6

Algorithm for Urinalysis Decision-Making

1. Patient presents with urinary symptoms?

   • Yes → Order urinalysis
   • No → Continue to next question

2. Patient has risk factors requiring screening? (pregnancy, pre-urologic procedure)

   • Yes → Order urinalysis
   • No → Continue to next question

3. Patient has suspected renal disease? (edema, hypertension, abnormal creatinine)

   • Yes → Order urinalysis with microscopy
   • No → Continue to next question

4. Patient has hematuria or proteinuria on previous testing?

   • Yes → Order complete urinalysis with microscopy
   • No → Urinalysis not indicated 1, 2

Remember that in patients with long-term indwelling catheters, bacteriuria and pyuria are virtually universal and should not be treated unless symptomatic 1. The presence of bacteria in urine does not necessarily indicate infection requiring treatment, particularly in asymptomatic elderly patients 2, 5.