It happens more often than people talk about: You go to the bathroom, and suddenly you notice red or brownish urine in the toilet bowl. Your heart skips a beat. Is it something you ate? Could it be serious? Should you wait or call your doctor?

If you ever see blood in your urine, don’t panic, but don’t ignore it either. That red color, whether it’s faint pink or dark like cola, might be your body’s way of sending a warning sign.

Let’s talk about what this means, what might be causing it, and why hematuria, the medical term for blood in the urine, deserves proper attention.

What is hematuria?

The word hematuria comes from the Greek: haima (αἷμα) meaning blood, and ouron (οὖρον) meaning urine. It refers to the presence of red blood cells in the urine.

There are two types:

• Gross hematuria: When blood is visible to the eye. The urine may look pink, red, or brown.
• Microscopic hematuria: Blood isn’t visible but is detected during a urine test under a microscope.

You don’t have to feel pain for hematuria to be significant. In fact, painless hematuria could possibly be the first sign of something serious.

How common is microscopic hematuria?

It’s more common than people think.

According to the American Urological Association (AUA), the prevalence of microscopic hematuria in adults varies from 2.4 percent to as high as 31.1 percent, depending on age, gender, and how the test is done.

In one study, 8.6 percent of healthy men screened at a public health event had blood in their urine, despite having no symptoms.

So while hematuria might seem rare, it’s actually a common finding, especially in routine screenings.

What causes blood in the urine?

There are many possible causes, some harmless, others more serious.

Common, often treatable causes:

• Urinary tract infections (UTIs)
• Kidney or bladder stones
• Benign prostatic hyperplasia (BPH)
• Vigorous exercise (especially long-distance running)
• Menstruation or contamination from the vagina or anus
• Certain medications like blood thinners or painkillers

More serious causes:

• Bladder cancer
• Prostate cancer
• Kidney cancer or glomerular diseases
• Tuberculosis of the urinary tract
• Radiation or surgical injury
• Inherited kidney disorders

Painless gross hematuria in men over 50 should be considered bladder cancer until proven otherwise.

What does it look like?

• Bright red or pink urine often signals fresh bleeding.
• Brown or tea-colored urine may suggest older blood from the kidneys.
• Cloudy urine with foul odor could indicate infection.

When in the stream the blood appears also gives clues:

• Start of urination → likely urethral origin
• End of urination → possibly bladder neck or prostate
• Throughout the stream → bladder or kidneys

Even if the bleeding is mild or occurs only once, it should not be ignored.

Does it hurt?

Not always.

• Painful hematuria is often caused by infections or stones.
• Painless hematuria is more worrisome, especially in older adults, because it can signal cancer or kidney disease.

The AUA Guidelines recommend that anyone over 35 with visible blood in their urine should undergo a full evaluation, regardless of whether they feel symptoms.

How is it diagnosed?

When we investigate hematuria, we typically start with:

• Urinalysis
• Urine culture (to check for infection)
• Blood tests (to check kidney function and, in men, PSA)
• Ultrasound or CT scan of the urinary tract
• Cystoscopy (a camera to inspect the bladder)
• Red blood cell morphology (to check if the bleeding is from the kidneys)

A 2018 review explains that there is no single universal guideline for evaluating hematuria. Instead, doctors tailor the workup based on your age, history, and symptoms, a method called risk-adapted evaluation.

How is it treated?

We don’t treat the bleeding itself; we treat what’s causing it:

• Infections → antibiotics
• Stones → medication, procedures, or surgery
• Cancer → surgery, immunotherapy, or systemic therapy
• BPH → medications or minimally invasive procedures
• Heavy bleeding → catheterization and bladder irrigation to clear clots

What if all the tests are normal?

This is called idiopathic microhematuria, meaning blood in the urine with no identifiable cause.

In younger patients, this is fairly common and often benign.

That said, persistent hematuria, even if painless and without a known cause, should be followed over time, especially in adults, to rule out subtle kidney disease or early changes.

Final thoughts

Blood in the urine should never be considered normal. While not every episode is a sign of serious pathology, hematuria is always a clinically relevant finding that warrants appropriate attention. In many cases, the underlying cause may be benign, such as a urinary tract infection, minor trauma, physical exertion, or a transient irritation. These can often be managed effectively with conservative measures once properly diagnosed.

However, hematuria can also be the initial and only symptom of significant urological conditions, including malignancies of the bladder, kidneys, or prostate. These diseases may progress silently and remain asymptomatic until advanced stages, making early recognition through subtle signs such as hematuria critical for timely intervention.

From a clinical standpoint, any presence of blood in the urine, whether gross or microscopic, painful or painless, should prompt a systematic evaluation. A thorough workup not only allows us to exclude potentially life-threatening causes but also provides reassurance to the patient when no significant pathology is found.

In my practice, I have seen the value of early diagnostic engagement. Delayed assessment often leads to missed opportunities for early-stage detection, particularly in patients who remain asymptomatic otherwise. Therefore, my message to both patients and referring colleagues is clear: if hematuria is identified, even once, it should be investigated.

Early evaluation is not just about uncovering serious disease; it is also about establishing clarity, preventing progression, and ensuring that we uphold the standard of care in every case, regardless of how trivial the symptom may initially appear.

Martina Ambardjieva is a dedicated urologist and medical educator with extensive experience in both clinical practice and academic instruction. She earned her MD from the University “Sv. Kiril i Metódij” in Skopje and is a PhD candidate in urological oncology, with a focus on bladder carcinoma. Her scholarly work includes numerous publications in oncologic urology, urinary calculosis, and men’s health.

Dr. Ambardjieva currently serves as a urologist at the PHI University Surgical Clinic “Naum Ohridski” and completed her residency training at the University Urology Clinic in Skopje. Earlier in her career, she practiced as a general medical doctor at Sante Plus General Hospital and completed a medical internship at the University of Ljubljana.

In addition to her clinical responsibilities, Dr. Ambardjieva is a teaching assistant at the Medical Faculty in Skopje. She works additionally as a collaborator for Dr. Telx. She has held leadership positions in the European Medical Students’ Association and actively participates in international medical education and policy. She has attended numerous congresses and workshops in France, Italy, Canada, and Turkey, and serves as a delegate for the European Association of Urology (EAU), contributing to cross-border initiatives in urology. Certified in laparoscopic surgery, she continues to integrate patient care, research, and education in her professional work.