Two kinds of hematuria
- Gross hematuria — visible blood or pink/red urine
- Microscopic hematuria — detected on urinalysis (≥3 RBC/HPF), not visible to the eye
Common causes
UTI, kidney or bladder stones, benign prostatic enlargement, vigorous exercise, menstruation, medications (including anticoagulants), and — importantly — bladder, upper-tract, and kidney cancers. Anticoagulation does not "explain away" hematuria; those patients still need workup.
Evaluation
A hematuria workup typically includes:
- Urinalysis and urine culture (to rule out infection first)
- Cystoscopy — direct look at the bladder and urethra
- Cross-sectional imaging (CT urogram or MR urogram) of the kidneys and ureters
- Risk-stratified follow-up based on age, smoking history, and findings
Red flags for prompt care
- Visible blood or clots
- Inability to urinate ("clot retention")
- Flank pain, fever, or systemic symptoms
If you are seeing blood, don't wait. Contact a clinician promptly.