Moderate severity22% reported by patientsICD-10: R31.9
Summary
The presence of red blood cells in the urine, which may be visible (gross hematuria) or detected only on urinalysis (microscopic hematuria).
What is it?
Hematuria can be gross (urine visibly red or brown) or microscopic (detected only by urinalysis). It is never normal in adults and always warrants evaluation. Common causes include urinary tract infections, kidney stones, and benign prostatic hyperplasia. However, painless gross hematuria is a red flag for bladder or kidney cancer until proven otherwise, especially in older adults and smokers. A single episode of visible blood in the urine should not be attributed to exercise or minor trauma without full evaluation.
Common causes
Lower Urinary Tract
Urinary tract infection
Bladder cancer
Bladder stones
Benign prostatic hyperplasia
Urethritis
Upper Urinary Tract
Kidney stones (nephrolithiasis)
Kidney cancer
Glomerulonephritis
Polycystic kidney disease
IgA nephropathy
Systemic
Anticoagulant medications (warfarin, apixaban)
Bleeding disorders
Sickle cell disease
Endocarditis
Non-Pathological
Strenuous exercise (runner's hematuria — resolves in 72 hours)
Foods (beets, blackberries — pink/red discoloration, not true blood)
When to see a doctor
1Any visible blood in urine in an adult — should be evaluated even if painless
2Hematuria with flank pain radiating to the groin (kidney stone)
3Blood in urine with fever, burning urination, or urinary urgency (UTI)
4Hematuria in a smoker over age 40 — increased bladder cancer risk
5Microscopic hematuria on routine urinalysis — requires follow-up evaluation
6Blood in urine after starting a blood thinner medication
What you can do
✓Increase fluid intake — hydration dilutes urine and may help pass small kidney stones
✓Avoid aspirin and NSAIDs until evaluated — they can worsen bleeding
✓Do not assume blood in urine is from a prior UTI without confirmation
✓Track whether blood appears at the beginning, throughout, or end of urination — guides localization
This page is for informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always consult your doctor or a qualified health provider with questions about your symptoms or medical conditions.
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