Prostate / Bladder / Kidney cancer
Visible blood in urine (hematuria) or semen (hematospermia)
Pink, red, or tea-colored urine. Blood streaks or spots in semen. Sometimes visible only in the toilet bowl. Sometimes only picked up on a urine dipstick as "microscopic hematuria" on routine labs.
What it could mean
Blood in urine can be a sign of prostate cancer, bladder cancer, kidney cancer, or a urinary tract cancer higher up. Bladder cancer in particular is often missed because "one episode of blood" gets attributed to a UTI without follow-up. Microscopic hematuria. The kind picked up on lab tests; has cancer as a cause in roughly 5% of cases, which is high enough to always work up.
What it probably is (to be fair)
UTIs (especially in women). Kidney stones. Prostate enlargement. Recent vigorous exercise. Menstrual contamination. Certain medications and foods (beets, some dyes). These are far more common than cancer. But hematuria of any kind that isn’t clearly explained needs imaging.
Why this gets dismissed
If you had one episode of bloody urine, got treated for a UTI, and never had a follow-up urine test to confirm the blood was gone. You got half a workup. The rule: hematuria that doesn’t clear with treatment needs imaging and cystoscopy.
For microscopic hematuria on lab tests: the current guideline is CT urogram plus cystoscopy for anyone over 35 with any risk factor (smoking, chemical exposure, family history, or the blood persisting). Most PCPs will say "recheck in 6 months." That’s not the guideline. That’s their comfort level.
When to call your doctor
- Any visible blood in urine, even one episode
- Any blood in semen (especially over 40, or persistent)
- Microscopic hematuria on any routine urinalysis
- Painful urination with blood
- Flank (side) pain with blood in urine
When to go to the ER
- Heavy bleeding with clots in urine
- Blood in urine with high fever (possible pyelonephritis/urosepsis)
- Blood in urine with severe flank pain
If you're dismissed
Ask for imaging directly: "Can we get a CT urogram to rule out an upper tract source? And a urology referral for cystoscopy if the blood persists?" Both of those are standard workup for hematuria over 35. Anything less is a shortcut.