Blood in Urine (Hematuria): What It Means | Dr. Theodore Cisu

The short answer: Blood in the urine, called hematuria, can be visible (pink, red or cola-colored urine) or found only under a microscope. It often has a harmless cause such as an infection, a stone or an enlarged prostate, but it can also be an early sign of bladder or kidney cancer. Visible blood should always be checked by a urologist. For microscopic blood, the AUA guideline matches the amount of testing to your personal risk.

Written by Theodore Cisu, MD, board-certified urologist. Based on the American Urological Association (AUA) and Society of Urodynamics, Female Pelvic Medicine and Urogenital Reconstruction (SUFU) guideline on microhematuria (2020, amended 2025). Last reviewed November 2026.

Ready to talk it through? Book a telehealth or in-person visit. No referral needed.

What is hematuria?

There are two types:

• Visible (gross) hematuria: You can see blood or clots in the urine. This deserves a urology visit even if it happened only once and went away on its own.
• Microscopic hematuria (microhematuria): The urine looks normal, but red blood cells show up on a urine test. The AUA defines this as 3 or more red blood cells per high-power field on a microscope exam of a properly collected urine sample.

A positive dipstick test alone isn't enough to make the diagnosis. The guideline calls for a urine test under the microscope to confirm it before any further workup.

Some things turn urine red or brown without any blood, such as beets, certain medicines and food dyes. A period can also show up in a urine sample.

What causes blood in the urine?

• Urinary tract infection
• Kidney or bladder stones
• An enlarged prostate (BPH)
• Hard exercise
• A recent urinary catheter or procedure
• Kidney diseases that affect the kidney's filters, which often come with protein in the urine
• Thinning of the vaginal and urethral tissues after menopause
• Cancer of the bladder, kidney or, less often, the ureter or prostate

Most people with microscopic blood don't have cancer. Still, bladder cancer often shows up first as blood in the urine, which is why evaluation matters.

A note on blood thinners: Medicines like warfarin, apixaban or aspirin can make bleeding more noticeable. The AUA guideline advises that blood in the urine still be evaluated in people taking these medicines, because they don't explain it on their own.

Who is at higher risk?

According to the AUA, the chance of finding cancer ranges from nearly zero in people with few risk factors to more than 6% in people with significant risk factors. Factors the guideline uses to estimate your risk include:

• Age and sex. Risk rises with age, and the age thresholds differ for men and women. Since 2025, women are no longer placed in the highest-risk group based on age alone.
• Smoking history, including how much you've smoked
• How much blood is in the urine, and whether it shows up again on repeat tests
• Any history of visible blood
• Other risk factors, such as work exposure to certain chemicals, past pelvic radiation, certain chemotherapy drugs, or a family history of bladder or kidney cancer or Lynch syndrome

How is hematuria evaluated?

The first step is a history, an exam and a urine test under the microscope. Your doctor may also check kidney function with a blood test. If an infection is likely, it's treated first, and the urine is rechecked afterward. If there are signs of kidney disease, such as protein in the urine, a kidney specialist may be involved.

From there, the AUA guideline places people into risk groups. Under the 2025 amendment, the plan generally looks like this.

Low or negligible risk

Instead of jumping straight to scopes and scans, the urine test is usually repeated within six months. If the repeat test is clear, no further testing is typically needed right now. If blood is still there, your risk group is reassessed and testing may follow. You and your urologist can still choose earlier testing if you have symptoms or concerns.

Intermediate risk

The usual evaluation is a cystoscopy to look inside the bladder plus an ultrasound of the kidneys. After talking it through, some people choose to delay cystoscopy. In that case, a urine test for cancer cells or a validated urine marker test is done along with an ultrasound of the kidneys and bladder. If blood is still present on a repeat urine test within a year, cystoscopy is recommended.

High risk, including visible blood

The evaluation includes a cystoscopy plus detailed imaging of the kidneys and ureters. A CT urogram, a CT scan with contrast dye timed to show the whole urinary tract, is preferred when it's safe for you. If you can't have CT contrast, an MRI or another imaging approach can be used.

The guideline also recommends imaging of the kidneys for anyone with a family history of kidney cancer, a known inherited kidney tumor syndrome or Lynch syndrome, whatever their risk group.

What cystoscopy is like

Office cystoscopy uses a thin, flexible camera passed through the urethra after numbing gel is applied. You're awake, it takes a few minutes, and you go home right afterward. Mild burning with urination for a day or so is common. Dr. Cisu performs office cystoscopy at his clinics.

What happens after a normal evaluation?

Most evaluations don't find cancer. Afterward, you and your urologist decide together whether to repeat a urine test in the future. If you later notice visible blood, new urinary symptoms or more blood on a urine test, it's time for another look.

When to see a urologist

• Any visible blood in the urine, even once
• Microscopic blood that places you in the intermediate or high-risk group
• Microscopic blood that's still there on a repeat test
• Blood in the urine with urinary symptoms not explained by an infection
• A current or past smoker with any blood in the urine

Go to the emergency room if you can't urinate, are passing large clots, are bleeding heavily, feel lightheaded, or have fever with back or side pain.

Seeing Dr. Cisu for blood in the urine

You can start with a telehealth visit from anywhere in Virginia. Our office can request your urine tests, labs and any CT or ultrasound images so Dr. Cisu reviews them before you talk and explains your risk group and options. Second opinions are welcome. Cystoscopy and in-person visits are available at clinics in Charlottesville and Fishersville, and no referral is needed. Book an appointment.

Frequently asked questions

Is blood in the urine always serious?

No. It's often caused by something treatable, like an infection or a stone, and sometimes no cause is found. Because it can be an early sign of cancer, it's worth having it checked.

Can a UTI cause blood in the urine?

Yes. The urine is usually rechecked after the infection is treated. If blood is still there, further evaluation is recommended.

I take a blood thinner. Do I still need to be checked?

Yes. The AUA guideline advises evaluating blood in the urine in people on blood thinners the same way as in anyone else.

Does cystoscopy hurt?

Most people describe it as uncomfortable more than painful. Numbing gel is used, and the exam takes only a few minutes.

Why would I need a CT scan?

A CT urogram gives a detailed view of the kidneys and ureters, where the bladder camera can't reach. It's used mainly for people in the high-risk group.

The blood went away. Do I still need to be seen?

If you saw blood, yes. Visible blood that stops on its own still needs evaluation. For microscopic blood, your risk group guides the next step.

Can exercise cause blood in the urine?

Yes, hard exercise can. It usually clears within a few days. Your doctor may repeat the urine test after a period of rest.

Sources

• American Urological Association. Microhematuria: AUA/SUFU Guideline (2020, amended 2025).
• American Urological Association. AUA releases microhematuria guideline amendment (2025).

This article is for general education and isn't a substitute for medical advice. If you can't urinate, are passing large clots or are bleeding heavily, call 911 or go to the nearest emergency room.