What should I do if I have hematuria (blood in urine)?

What to Do If You Have Blood in Your Urine

If you can see blood in your urine with your naked eye (gross hematuria), you need urgent referral to a urologist immediately, even if the bleeding has stopped—the cancer risk exceeds 10% and can be as high as 25-40% in some cases. 1

Immediate Action Based on Type of Hematuria

If You Have Visible Blood (Gross Hematuria)

Seek urologic evaluation urgently, regardless of whether the bleeding has resolved. 1 The American College of Physicians explicitly states that all adults with gross hematuria require urologic referral even if self-limited. 1

• Painless gross hematuria has a particularly strong association with cancer and requires immediate attention 1
• Gross hematuria with flank pain suggests kidney stones but still requires full evaluation 1
• The malignancy risk with gross hematuria consistently exceeds 10% and reaches 25-40% in referral series 1, 2

If Blood Is Only Detected on Testing (Microscopic Hematuria)

First, confirm true microscopic hematuria with proper testing before pursuing extensive workup. 1

Step 1: Confirm the Finding

• Request microscopic urinalysis showing ≥3 red blood cells per high-power field on at least two of three properly collected clean-catch midstream urine specimens 1, 3
• Dipstick tests alone have only 65-99% specificity and produce false positives—they must be confirmed microscopically 3, 4
• Do not proceed with imaging or cystoscopy based on dipstick alone 3

Step 2: Exclude Simple Benign Causes

• Get urine culture to rule out urinary tract infection 2, 5
• Consider whether you had vigorous exercise within 24-48 hours (can cause transient hematuria) 3
• In women, ensure the sample wasn't contaminated by menstruation 3

Step 3: Assess Your Cancer Risk

High-risk features requiring full urologic evaluation: 3, 6

• Any history of visible blood (even if current testing shows only microscopic hematuria) 1, 3
• Age >35-40 years (men ≥60 years are highest risk) 3, 6
• Smoking history (especially >30 pack-years) 3, 6
• Occupational exposure to chemicals/dyes (benzenes, aromatic amines) 3, 6
• Irritative voiding symptoms (urgency, frequency) without infection 3, 6

Complete Urologic Evaluation (When Indicated)

If you have confirmed microscopic hematuria with risk factors or any gross hematuria, you need: 3, 6

Upper Urinary Tract Imaging

• Multiphasic CT urography is the preferred test to detect kidney cancer, bladder cancer, and stones 3, 6
• This includes unenhanced, nephrographic, and excretory phases to comprehensively evaluate kidneys, ureters, and bladder 3
• If CT is contraindicated (kidney disease, contrast allergy), MR urography or ultrasound with retrograde pyelography are alternatives 3

Lower Urinary Tract Evaluation

• Cystoscopy is mandatory for all gross hematuria and high-risk microscopic hematuria 3, 2
• Flexible cystoscopy is preferred over rigid (less pain, equivalent accuracy) 3
• This directly visualizes the bladder lining to detect bladder cancer 3

Laboratory Tests

• Serum creatinine to assess kidney function 3, 2
• Complete urinalysis with microscopy 3
• Do NOT obtain urine cytology or molecular markers in initial evaluation—these are not recommended 1, 4

Critical Pitfalls to Avoid

Never Attribute Hematuria to Blood Thinners

If you take anticoagulants (warfarin, apixaban, rivaroxaban) or antiplatelet drugs (aspirin, clopidogrel), you still need full evaluation. 1, 2 The American College of Physicians explicitly states that evaluation should proceed even in patients taking these medications—they may unmask underlying pathology but do not cause hematuria themselves. 1, 2, 4

Don't Assume Infection Explains Everything

• Even if you have a urinary tract infection, gross hematuria requires follow-up confirmation after infection treatment 2
• Recurrent infections can mask malignancy 3

Don't Ignore Self-Limited Bleeding

• Even one episode of visible blood requires evaluation, regardless of whether it resolved 1
• Hematuria can precede bladder cancer diagnosis by many years 3

When to Consider Kidney Disease Instead

Refer to nephrology (not urology) if you have features suggesting glomerular (kidney filter) disease: 3, 6

• Tea-colored or cola-colored urine (not bright red) 3, 6
• Significant protein in urine (protein-to-creatinine ratio >0.2) 3
• Elevated creatinine or declining kidney function 3
• Red blood cell casts on microscopy (pathognomonic for glomerular disease) 3
• >80% dysmorphic red blood cells on phase contrast microscopy 3

Follow-Up If Initial Workup Is Negative

If your complete evaluation finds no cause but microscopic hematuria persists: 3, 5

• Repeat urinalysis at 6,12,24, and 36 months 3
• Check blood pressure at each visit 3
• Immediate re-evaluation if you develop: 3
  • Visible blood
  • Significant increase in microscopic hematuria
  • New urinary symptoms
  • High blood pressure, protein in urine, or signs of kidney disease

Special Populations

Children

• Isolated microscopic hematuria without protein or dysmorphic RBCs typically doesn't require imaging 3
• Ultrasound is preferred over CT if imaging is needed 3

Elderly Males

• Men ≥60 years are automatically high-risk and require cystoscopy and CT urography regardless of other factors 3
• Benign prostatic hyperplasia can cause hematuria but does not exclude concurrent cancer 3

The bottom line: Visible blood always requires urgent urologic evaluation. Microscopic hematuria confirmed on proper testing requires risk stratification and often complete urologic workup to exclude cancer, which can be detected early when most treatable. 1, 3, 2