Painless Blood in Urine: Causes and Next Steps

What does painless blood in the urine mean?

Hematuria is the medical term for blood in the urine. It is called gross hematuria when the blood is enough to change the color of the urine (pink, red, or brown), and microscopic hematuria when it is too small to see but shows up on a urine test.

The absence of pain is not reassuring from a diagnostic standpoint. Several serious conditions — most notably bladder cancer — often present with painless hematuria. Pain is more associated with kidney stones passing through the ureter or with urinary tract infections, both of which also cause hematuria. Painless hematuria, by contrast, is a classic early sign of bladder or kidney tumors.

This does not mean that painless hematuria is usually cancer — the majority of cases have benign explanations. But because the stakes are high, the evaluation is always warranted.

What are the most common causes of blood in the urine without pain?

Urological causes that commonly produce painless hematuria include: 1Ref 1National Cancer Institute (2023).Bladder Cancer Symptoms.Hematuria — including painless, intermittent gross hematuria — as the most common presenting symptom of bladder cancer; other urological causes enumerated

• Bladder cancer — the most important condition to rule out. It is a common cause of gross painless hematuria in adults over 50, particularly in smokers
• Kidney (renal) tumors — can bleed into the urine without causing pain, especially early in their course
• Kidney stones — some stones sit in the kidney or bladder without causing obstruction and may bleed without pain 3Ref 3National Institute of Diabetes and Digestive and Kidney Diseases (2023).Definition & Facts for Kidney Stones.Kidney stones as a benign cause of painless hematuria when a stone sits in the kidney without obstruction
• Urinary tract infection — occasionally hematuria from a UTI is the presenting symptom, even before burning or frequency develops
• Benign prostatic hyperplasia (BPH) — an enlarged prostate can compress the bladder neck and cause bleeding
• Cystitis — bladder inflammation without infection (interstitial cystitis) or after radiation
• Vigorous exercise — runners and cyclists sometimes have transient hematuria after prolonged exertion, which typically resolves within 24–48 hours
• Medications — blood thinners (anticoagulants), certain antibiotics, and other drugs can cause hematuria
• Glomerulonephritis — inflammation of the kidney's filtering units, which can leak blood into the urine; usually also causes protein in the urine and abnormal kidney function tests
• Benign causes — in some cases, after complete evaluation, no specific cause is identified

Does the color of the urine help identify the cause?

To a limited degree. Bright red urine suggests more active or recent bleeding, often from the bladder or lower urinary tract. Brown or tea-colored urine can indicate older blood or bleeding from the kidneys, and can sometimes signal a kidney inflammatory condition.

However, color alone cannot reliably identify the source or cause. Other substances can change urine color — beets, certain foods, some medications, and myoglobin from muscle injury can all produce red or dark urine without any blood being present. A urine test (urinalysis with microscopy) is needed to confirm that the color change is actually from red blood cells.

What evaluation is needed for painless hematuria?

A urologist will take a thorough history and may recommend: 1Ref 1National Cancer Institute (2023).Bladder Cancer Symptoms.Hematuria — including painless, intermittent gross hematuria — as the most common presenting symptom of bladder cancer; other urological causes enumerated2Ref 2Barocas DA, Boorjian SA, Alvarez RD, et al. (2020).Microhematuria: AUA/SUFU Guideline.Risk-stratified evaluation framework for hematuria (low/intermediate/high risk); indications for cystoscopy, upper-tract imaging, and urine cytology

• Urinalysis with microscopy — confirms blood cells in the urine and checks for protein, casts, or infection
• Urine culture — rules out a urinary tract infection as the cause
• Urine cytology — looks for abnormal (potentially cancerous) cells shed from the bladder or upper urinary tract
• CT urogram — a specialized CT scan with contrast that images the kidneys, ureters, and bladder, excellent for detecting tumors and stones
• Cystoscopy — direct visual examination of the inside of the bladder; often needed if no clear cause is found on initial testing
• Blood tests — kidney function (creatinine), blood pressure assessment; referral to nephrology if a glomerular cause is suspected

The AUA/SUFU 2020 guideline stratifies patients with microhematuria into low, intermediate, and high risk for genitourinary malignancy, with the workup intensity calibrated to that risk level — including age, sex, smoking history, and episode type. 2Ref 2Barocas DA, Boorjian SA, Alvarez RD, et al. (2020).Microhematuria: AUA/SUFU Guideline.Risk-stratified evaluation framework for hematuria (low/intermediate/high risk); indications for cystoscopy, upper-tract imaging, and urine cytology

What should I do if my urine test shows blood but I feel fine?

Follow through on the evaluation, even if you feel completely well. Incidental microscopic hematuria found on a routine test is a common clinical scenario — and while many cases turn out to have a benign explanation or no identifiable cause, the workup is still important to ensure nothing serious is missed.

Gale can help coordinate a referral to a urologist and help you understand what to expect during your evaluation.