If you can see blood in your urine, get it evaluated — even if it happened once, even if it didn't hurt, even if it has already cleared. Most causes turn out to be treatable and not cancer. But painless visible blood is the most common first sign of bladder cancer, and it characteristically comes and goes, which is exactly why people wait. Blood found only on a dipstick or under a microscope also needs a proper follow-up, not a shrug.
This page will not tell you that you're probably fine. A urine result is a clue, not a diagnosis, and only a clinician who can examine you and see your full history can interpret it. What this guide can do is tell you what's urgent tonight, what's urgent this week, and what a real work-up looks like — so you can tell whether you got one.
What counts as "blood in the urine"?
Clinicians split hematuria into two kinds, and the difference changes what happens next.
- Visible (gross) hematuria. You can see it. Urine looks pink, red, rusty, tea-colored or cola-colored, or you pass clots. The National Cancer Institute describes the color as anything from slightly rusty to bright red. It takes only a tiny amount of blood — on the order of a milliliter in a full bladder, well under a teaspoon — to color an entire void, so the shade tells you nothing about how much you are bleeding.
- Microscopic hematuria (microhematuria). You see nothing; a lab does. The American Urological Association (AUA) and SUFU guideline defines it as 3 or more red blood cells per high-power field on microscopy of a single, properly collected urine sample.
One detail matters a lot: a positive dipstick alone is not microhematuria. The AUA is explicit that clinicians should not define microhematuria by dipstick testing alone — it has to be confirmed by looking at the urine under a microscope, because at least 20% of dipsticks that read positive for blood show no red blood cells at all on microscopy. The dipstick reacts to heme, so it can also flip positive from muscle breakdown products, free hemoglobin, or menstrual contamination. If you were handed a positive dipstick and no microscopy, the correct next step is microscopy on a properly collected sample — not reassurance, and not antibiotics on spec.
Our urinalysis decoder walks through what each line on the report means, and the lab results explainer covers the blood tests that usually go with it. Reference ranges and reporting cut-offs vary between labs; a result is a clue to be read in the context of you, by someone who can examine you.
Is it definitely blood? What else turns urine red or brown
Some red urine isn't blood, and some brown urine is something worse than blood. Never use this table to talk yourself out of an appointment — use it to give your clinician better information.
| What it is | Typical look | What to do |
|---|---|---|
| Beets, blackberries, rhubarb, heavy food coloring | Pink or reddish, no pain, appears within a day of eating and clears within a day or two | Still mention it. If the color outlasts the food, or a dipstick is positive, it needs testing |
| Medications (e.g. rifampin, phenazopyridine, senna, nitrofurantoin, some laxatives) | Orange, red, or brown discoloration | Bring your medication list to the appointment; do not stop anything on your own |
| Menstrual or vaginal bleeding contaminating the sample | Blood on the dipstick with no urinary symptoms | Very common at midlife with irregular perimenopausal bleeding. The sample must be repeated when you're not bleeding — a repeat, not a dismissal |
| Muscle breakdown (rhabdomyolysis) after extreme exertion, a fall, or a long lie | Dark cola or tea color, severe muscle aching or weakness, little urine | Urgent — same-day care. The dipstick can read "blood" with no red cells present. This can injure the kidneys |
| Liver or bile problems | Deep brown urine, pale stools, yellowing of eyes or skin | See a doctor promptly — this isn't a urinary-tract issue |
If you want to compare shades and what they generally signal, see our urine color chart.
What causes blood in the urine?
Causes range from trivially benign to time-critical. The honest summary: the list is wide, and you cannot narrow it down from home.
| Cause | Clues that point to it | Urgency |
|---|---|---|
| Urinary tract infection | Burning, urgency, frequency, cloudy or strong-smelling urine, lower-abdominal ache | See a clinician within 1–2 days. Sooner if fever, chills, nausea or back/side pain — that suggests the kidney |
| Kidney or bladder stone | Severe waves of pain in the flank radiating to the groin, nausea, restlessness | Same day. Emergency if fever, vomiting, or you cannot pass urine |
| Vigorous exercise ("runner's hematuria") | Follows a hard run, ride, or heavy session; no pain; settles within about 72 hours of rest | Still needs a confirming repeat test after rest. If the blood persists, it is not exercise |
| Menstrual or vaginal blood in the sample | Positive dipstick, no urinary symptoms, you're bleeding or spotting | Repeat the sample when not bleeding. Never assume — confirm |
| Enlarged prostate (men) | Weak stream, dribbling, getting up at night; more common over 50 | Routine, but it does not excuse skipping the work-up — an enlarged prostate never explains hematuria until other causes have been ruled out |
| Kidney (glomerular) disease | Tea or cola color, foamy urine, protein in the urine, ankle swelling, raised blood pressure | Prompt referral, usually to a kidney specialist rather than a urologist |
| Bladder, kidney or urothelial cancer | Often painless visible blood that comes and goes. Risk rises with age and with smoking history | Highest priority. Full urological evaluation, regardless of how brief the episode was |
| Recent catheter, procedure, or trauma to the area | Blood within days of the event | Report it — do not assume it explains itself |
| Sickle cell trait or disease, clotting disorders | Known diagnosis or family history | Discuss with the clinician who manages that condition |
Go to urgent care or the ER now if…
Do not wait for a routine appointment if you have any of the following:
- You cannot pass urine, or you can only pass a dribble while your bladder feels painfully full
- You are passing clots — clots can block the bladder outlet and cause retention
- Fever or chills with pain in your back, side, or groin — this can mean a kidney infection, which can turn serious quickly
- Severe pain anywhere in the abdomen, flank, or back that you cannot get on top of
- Feeling faint, lightheaded, breathless, or a racing heart — possible signs of significant blood loss or sepsis
- Persistent vomiting, so you can't keep fluids or medicines down
- Blood in the urine after an injury to your back, side, or abdomen
Why does painless blood matter more, not less?
This is the point most articles bury. Pain gets people to the doctor. Painless bleeding does the opposite — it feels less alarming, it usually stops on its own, and it may not come back for weeks. The National Cancer Institute lists blood in the urine as the most common symptom of bladder cancer, describes the color as anything from slightly rusty to bright red, and says plainly that you may see it once and then not see it again for a while.
So the reasoning "it stopped, so it must have been nothing" is precisely backwards. The episode you dismiss is the one that was trying to tell you something. One visible episode is enough to warrant a full evaluation. That is also the NHS position: ask for an urgent appointment for blood in your urine even if there is only a small amount, even if it is the first time it has happened, and even if you have no other symptoms.
None of this means you have cancer. Most people evaluated for hematuria turn out not to have it. It means the only way to move from "probably nothing" to "confirmed nothing" is a test.
Why are women more likely to be told "it's just a UTI"?
Because for women it usually is a UTI — and that base rate does real damage. Blood, burning and urgency in a woman get treated as cystitis by pattern-match. When the same symptoms come back, they get treated as cystitis again. This is measurable, not anecdotal: in a nationwide claims analysis of nearly 7,700 adults who were eventually diagnosed with bladder cancer after first presenting with hematuria, women waited longer for the diagnosis than men (a mean of 85 versus 74 days), were more than twice as likely to be labeled with a urinary tract infection first, and were less likely to be sent for abdominal or pelvic imaging.
Two things protect you, and both are things you can ask for by name:
- A urine culture, not just a dipstick, before another course of antibiotics — so that "UTI" is proven rather than assumed.
- A repeat urinalysis after treatment. If the infection was the cause, the blood should be gone once the infection is. Blood that persists after a treated UTI is an unexplained finding and needs a urology referral — this is the single most useful sentence in this article. The UK's NICE referral guidance says the same thing in clinical language: visible blood in the urine that persists or recurs after successful treatment of a UTI, in anyone aged 45 or over, triggers an urgent suspected-cancer referral.
More on the infection side of this in our guides to urinary tract infection and recurrent UTIs, and on what white cells on a result mean in leukocytes in urine.
What should happen when you get checked?
Expect a urine sample sent for microscopy and culture, a blood pressure reading, blood tests of kidney function, and a check for protein in the urine — protein alongside blood points toward the kidney's filters rather than the bladder, and that changes which specialist you are sent to.
Visible hematuria in an adult gets a full urological evaluation. There is no risk-scoring step that lets you out of it: it means imaging of the upper urinary tract and a look inside the bladder with a cystoscope.
For microhematuria confirmed on microscopy, the AUA/SUFU guideline (published 2020, amended February 2025) sorts adults into risk tiers — which is why your age, smoking history and red-cell count get asked about. The 2025 amendment specifically changed the tiers for women: the low-risk age cut-off moved from under 50 to under 60, and women are no longer classed as high-risk on age alone.
| Risk tier | Roughly who (women) | Recommended evaluation |
|---|---|---|
| Low / negligible (all must apply) | Under 60, never-smoker or under 10 pack-years, 3–10 red cells per high-power field, no other urothelial-cancer risk factors | Repeat urinalysis within about 6 months rather than immediate cystoscopy or imaging |
| Intermediate (any one) | 60 or older, 10–30 pack-years, or 11–25 red cells per high-power field | Cystoscopy plus kidney ultrasound; a urine tumor marker may be discussed if cystoscopy is deferred |
| High (any one) | More than 30 pack-years, more than 25 red cells per high-power field, any history of visible blood, or other high-risk features — age alone does not put a woman in this tier | Cystoscopy plus CT urography (MR urography if contrast is contraindicated) |
These are clinician thresholds from a US guideline, and they do change — the women's age cut-off moved by a decade in the 2025 amendment. Other countries stratify differently, and reporting cut-offs vary between labs. They are here so you can recognize whether the plan you were given fits a recognized standard, not so you can grade yourself.
Does menopause, HRT, or a blood thinner explain it away?
No — and this is where midlife women get short-changed most often.
- Blood thinners. Being on warfarin, a DOAC, or aspirin is not an explanation for blood in the urine. Anticoagulation can unmask bleeding from something that was already there; it does not create it out of nothing. Being on one changes nothing about needing the work-up — and you should never stop or adjust the medication yourself.
- Vaginal and urethral changes after menopause. Thinning tissue can bleed and can genuinely contaminate a sample, and it is worth an exam. But "it's probably atrophy" is a conclusion you are allowed to reach only after the urinary tract has been checked, never instead of checking it. See bladder changes at menopause.
- Perimenopausal bleeding. Unpredictable cycles make it genuinely hard to know whether blood came from the bladder or the vagina. The answer is a repeat sample on a non-bleeding day — not a guess.
If bleeding of any kind has been heavy or prolonged, ask about iron status too; low iron is common at midlife and easy to miss. Get tested and let a clinician decide what, if anything, to do about it — see iron deficiency anemia.
When to see a doctor
See a clinician urgently — within days, not weeks — if:
- You see blood in your urine even once, even briefly, even painlessly, even if you are not certain it was blood
- A dipstick or lab result showed blood and nobody has followed it up with microscopy
- Blood is still showing on a urine test after a UTI has been treated
- You have burning, urgency or frequency that keeps returning and keeps being treated as infection without a culture
- You have unexplained weight loss, ongoing back or side pain, or you smoke or used to smoke — smoking is the single biggest modifiable risk factor for bladder cancer
Go to the ER or urgent care today for any of the red flags above: inability to pass urine, clots, fever with flank pain, severe pain, faintness, or blood after an injury.
Do not treat yourself. Don't start leftover antibiotics, don't start an iron supplement to "replace" what you think you lost, and don't stop a prescribed blood thinner. Bring the sample, ask for the microscopy, and let the result be interpreted by someone who can examine you. More on the whole system in our bladder and urinary health hub.
