Blood in Urine (Hematuria): Is It Common in Cancer, What Causes It, and How Is It Managed?

Seeing blood in the urine called hematuria can be alarming, and it deserves medical evaluation even though there are many benign causes. Visible blood (gross hematuria) can sometimes be a sign of advanced cancers of the kidney, bladder, or prostate, but more common non‑cancer causes include infections, stones, and inflammation. ^{[1] [2]} Microscopic blood (found only on a urine test) can also have kidney-related causes like glomerulonephritis and, less often, be associated with cancer. ^[3]

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What Hematuria Looks Like

• Gross hematuria: Urine appears pink, red, or cola-colored; even a small amount of blood can change urine color. This may or may not be painful, but passing clots can hurt. ^{[1] [2]}
• Microscopic hematuria: Blood is only seen under the microscope during lab testing. ^[1]

Because red urine can also result from foods (like beets) or some medicines, it’s important to confirm whether red urine is truly blood. ^[4]

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Is Blood in Urine a Common Symptom of Cancer?

• Visible hematuria may be linked with genitourinary cancers, particularly bladder and kidney cancers, and sometimes prostate cancer, especially when it’s persistent or occurs in people with risk factors. ^{[1] [5]}
• Epidemiologic reviews suggest a notable minority of hematuria cases reveal urologic malignancy, with higher rates in gross hematuria than microscopic hematuria, underscoring the need for proper evaluation. ^[6]

Still, most cases are caused by non‑cancer conditions such as infections, stones, or inflammation, so evaluation aims to separate benign from serious causes. ^[7]

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Common Causes of Hematuria

• Urinary infections and inflammation: Cystitis (bladder infection), urethritis. ^[8]
• Kidney causes: Glomerulonephritis (inflammation of kidney filters) is a classic cause of microscopic hematuria. ^[3]
• Stones: Kidney or ureteral stones can scratch the lining and bleed. ^[8]
• Cancer: Bladder, kidney, or prostate cancers can cause visible blood in urine, especially in later stages. ^{[1] [5]}
• Inherited conditions: Sickle cell disease; Alport syndrome affecting kidney vessels. ^{[9] [5]}
• Exercise, trauma, medications, and other systemic conditions can also lead to hematuria. ^[8]

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When to Seek Care

• Any time urine looks like it has blood, you should see a healthcare provider to confirm and find the cause. ^[4]
• Seek urgent care if you have fever, nausea/vomiting, severe flank or abdominal pain, inability to urinate, or are passing clots, as these can indicate infection, blockage, or other emergencies. ^{[10] [11]}

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How Doctors Evaluate Hematuria

Evaluation is tailored to your risk level (age, smoking history, amount of blood, and whether it’s visible vs microscopic):

• Initial steps: History, physical exam, urinalysis, and urine culture to check for infection. Confirming true hematuria matters because foods and certain drugs can mimic red urine. ^[4]
• Risk-stratified testing: For higher-risk individuals (for example, age ≥60, ≥30 pack‑years smoking, ≥25 RBCs per high‑power field, or any gross hematuria), cystoscopy to look inside the bladder plus CT urography to image kidneys and ureters are generally recommended. ^{[12] [13]}
• Lower-risk microscopic hematuria: Options include repeat urine testing within about 6 months, or cystoscopy plus kidney ultrasound; if microscopic hematuria persists, repeat the evaluation. ^[14]
• Persistent hematuria after a negative workup warrants ongoing follow-up according to guideline frameworks. [PM21]

This approach aims to catch important causes like cancer while avoiding unnecessary procedures in low-risk cases. ^[12] [PM21]

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Management Depends on the Cause

• Infections: Antibiotics and recheck urine to ensure blood resolves. ^[8]
• Stones: Hydration, pain control, and sometimes procedures if stones are large or obstructing. ^[8]
• Glomerulonephritis or kidney diseases: Managed by kidney specialists, focusing on the underlying inflammation and kidney protection. ^[3]
• Cancer: If bladder cancer is found, first-line treatment for non‑muscle‑invasive disease is transurethral resection followed by risk‑based intravesical therapy (often BCG) to reduce recurrence and progression. [PM14] For muscle‑invasive or advanced disease, strategies may include surgery, chemotherapy, immunotherapy, and targeted agents. [PM14]
• Inherited conditions (e.g., sickle cell disease, Alport): Condition-specific management to reduce hematuria episodes and protect kidneys. ^{[9] [5]}

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Practical Tips While You Await Evaluation

• Note triggers and symptoms: Pain, clots, frequency, burning, or recent strenuous exercise; these details help your clinician. ^{[2] [8]}
• Hydration: Staying well hydrated can help reduce irritation and clot formation in some benign causes. ^[2]
• Avoid strenuous activity if exercise-induced hematuria is suspected until cleared. ^[8]
• Bring medication and supplement lists since some agents can discolor urine or affect bleeding. ^[4]

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Summary

Blood in urine is a symptom with a wide range of causes from infections and stones to, less commonly, cancers of the urinary tract and it always merits medical evaluation. ^[1] Visible blood is more concerning for potential cancer than microscopic blood, particularly in higher-risk individuals. ^[5] Modern, risk‑based guidelines use a combination of urine tests, cystoscopy, and imaging to identify serious causes while minimizing unnecessary testing, and treatment is tailored to the specific diagnosis. ^{[12] [14]} [PM21]

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