Blood in your urine, even once, deserves medical attention. Learn about possible causes, bladder and kidney cancer warning signs, and when to seek evaluation.
November 11, 2026
A little discomfort, more frequent trips to the bathroom or an unexpected change in urine colour can be easy to dismiss, especially when there are no other symptoms.
But one particular change should never be ignored: blood in your urine.
Known medically as hematuria, blood in the urine can be visible to the naked eye or detected only through laboratory testing. Sometimes urine appears pink, red or brownish. In other cases, it looks completely normal, and the presence of blood is discovered during a routine urine test.
Regardless of how it appears, blood in the urine deserves medical evaluation, even if it happens only once and disappears.
While there are several possible explanations, including urinary tract infections, kidney stones and other non-cancerous conditions, blood in the urine can also be an early warning sign of bladder or kidney cancer.
The important thing is not to assume the worst, but equally, not to assume everything is fine.
The urinary system includes the kidneys, ureters, bladder and urethra. These organs work together to filter waste from the bloodstream, produce urine and eliminate it from the body.
Blood can enter the urine when there is irritation, inflammation, injury or disease affecting any part of this system.
Some common causes include:
The challenge is that these conditions can produce similar symptoms. A person cannot reliably determine the cause based on urine colour, discomfort or the absence of pain.
This is why proper evaluation matters.
One of the reasons blood in the urine deserves particular attention is its association with bladder cancer.
Bladder cancer can cause visible blood in the urine without producing significant pain. Some men may notice a single episode of discoloured urine and then see no further changes for weeks or months.
That temporary disappearance does not necessarily mean the underlying cause has resolved.
Other possible warning signs include:
These symptoms can also be caused by infections and other common conditions. However, persistent or unexplained changes should be assessed by a healthcare professional.
Smoking is an important risk factor for bladder cancer. Certain occupational chemical exposures and increasing age can also influence risk.
Kidney cancer can develop without noticeable symptoms during its earlier stages.
When symptoms do occur, they may include blood in the urine, persistent discomfort in the side or back, unexplained weight loss, fatigue or a palpable mass in the abdomen.
However, many of these symptoms are associated with other medical conditions.
This is one reason a physician should consider the broader clinical picture rather than focusing on one symptom in isolation.
Your age, medical history, family history, smoking history, previous test results and other health factors can all influence what investigations may be appropriate.
An evaluation for blood in the urine typically begins with a conversation about your symptoms and medical history.
Your physician may ask:
Depending on the findings, investigations may include a urinalysis, urine culture, blood tests to assess kidney function, imaging of the urinary tract or referral to a urologist.
In some cases, a cystoscopy may be recommended. This procedure allows a specialist to examine the inside of the bladder using a small camera.
The appropriate evaluation depends on individual risk factors and clinical findings. Not every person requires every test.
Men sometimes delay medical appointments because a symptom disappears, becomes less noticeable or doesn't interfere with daily activities.
Unfortunately, the absence of ongoing discomfort does not always mean the absence of an underlying problem.
Blood in the urine should be evaluated even if it happens once, even if there is no pain and even if you otherwise feel healthy.
If you are passing visible blood or blood clots, contact a healthcare professional promptly. Seek emergency care if you cannot urinate, are passing significant clots, have severe pain, feel faint or experience heavy bleeding.
At Bespoke Concierge MD, we believe healthcare should extend beyond responding to symptoms.
Having a physician who understands your medical history, personal health goals and individual risk factors creates an opportunity for more informed conversations about prevention, investigation and long-term health.
A change in your health may seem minor, but understanding what it means requires looking at the bigger picture.
Your physician can help determine which tests, screenings and specialist evaluations may be appropriate based on your individual circumstances.
Don't dismiss blood in your urine, even if it happens only once. Speak with a physician and make sure the cause is properly evaluated.
Bespoke Concierge MD
A doctor who knows you, looks beyond today's symptoms and takes a proactive, personalized approach to your health.
If you have questions about your health history, recent test results or appropriate preventive evaluations, book a Discovery Call with a Bespoke physician.