What does blood in urine look like?

Urine may be pink, red, tea-coloured or brown. Sometimes blood is invisible — found only when a GP or nurse tests urine (non-visible haematuria). Even a single episode of visible blood needs assessment.

What causes blood in urine?

Common causes include urinary tract infections, kidney stones, an enlarged prostate in men, exercise-induced haematuria, and kidney inflammation. Less commonly, bladder or kidney cancer, blood clotting disorders, and certain medicines. A GP arranges tests to find the cause.

Can blood in urine be harmless?

Sometimes — vigorous exercise or minor infection can cause temporary blood. But because serious conditions including cancer can cause blood in urine, a GP should assess every episode to rule out important causes.

What tests will a GP do?

Urine tests, blood tests, and often referral for imaging — ultrasound or CT scan of kidneys and bladder. Men may have prostate examination; cystoscopy (camera into the bladder) may be recommended, especially over 45 or if tests are abnormal.

Is blood in urine a sign of cancer?

Bladder and kidney cancer can cause blood in urine — often without pain. It is not the most common cause, but early detection improves outcomes. This is why same-day GP assessment matters, especially for smokers and people over 45.

Blood in urine | HealthAnswers

Quick answer

What could blood in urine mean?

Blood in urine (haematuria) may appear pink, red or brown, or be found only on a urine test. Causes range from urine infections and kidney stones to — rarely — bladder or kidney cancer. See a GP the same day for visible blood in urine, especially if you are over 45 or smoke — urgent assessment rules out serious causes.

Blood in urine always needs checking

Blood in urine — haematuria — means red blood cells are present. It may be visible (the urine looks pink, red or brown) or non-visible (found only on a dipstick or laboratory test). Even a single episode of visible blood, or blood that appears once and stops, warrants same-day GP assessment because serious conditions — including bladder and kidney cancer — can be the cause.

What you might notice

urine that is pink, red, or tea-coloured
blood clots in urine (less common)
no visible change — blood detected on a routine urine test at the GP

Blood at the start of urination may suggest a urethral or prostate source. Blood throughout the stream may indicate bladder or kidney origin. Blood at the end may suggest bladder neck or prostate issues. A GP interprets the pattern alongside tests.

Common causes

Urinary tract infection (UTI) — burning when passing urine, frequency, and sometimes blood. More common in women.

Kidney stones — severe pain in the back or side, blood in urine. See our kidney stones guide.

Exercise-induced haematuria — long-distance running or intense exercise can cause temporary blood. Diagnosis of exclusion — other causes must be ruled out first.

Enlarged prostate (in men) — blood and urinary symptoms over 50.

Kidney inflammation (glomerulonephritis) — may cause blood with swelling and high blood pressure.

Medications — anticoagulants (blood thinners) increase bleeding risk but do not explain blood without another cause.

Bladder or kidney cancer — often causes painless visible blood. More common in smokers and people over 45. Early diagnosis improves treatment success.

When it is urgent

Call 999 if you:

cannot pass urine at all (retention)
have severe pain with blood and feel very unwell
have fever, rigors and blood in urine with flank pain (possible kidney infection)

See a GP the same day for any visible blood — even without pain, even if it happens once.

What assessment involves

A GP will usually arrange:

urine tests — infection, blood, protein
blood tests — kidney function
imaging — ultrasound or CT of kidneys and urinary tract
cystoscopy — camera examination of the bladder — may be recommended, especially if you are over 45, smoke, or have persistent blood

Assessment is structured to find treatable causes quickly.

Do not ignore it

Many people delay seeking help because blood appeared once and stopped, or because there is no pain. Painless visible haematuria is a classic presentation of bladder cancer — early detection saves lives. Same-day GP assessment is the right response every time.

Blood in urine and anticoagulants

If you take warfarin, apixaban, or similar medicines and notice blood in urine, see a GP the same day. Do not stop anticoagulants without medical advice — but the bleeding still needs investigation.

If you also have burning when urinating and frequency, a UTI may be the cause — but still needs confirmation. Flank pain with blood suggests kidney stones. A GP connects your symptoms to the right tests.

Common questions

What does blood in urine look like?: Urine may be pink, red, tea-coloured or brown. Sometimes blood is invisible — found only when a GP or nurse tests urine (non-visible haematuria). Even a single episode of visible blood needs assessment.
What causes blood in urine?: Common causes include urinary tract infections, kidney stones, an enlarged prostate in men, exercise-induced haematuria, and kidney inflammation. Less commonly, bladder or kidney cancer, blood clotting disorders, and certain medicines. A GP arranges tests to find the cause.
Can blood in urine be harmless?: Sometimes — vigorous exercise or minor infection can cause temporary blood. But because serious conditions including cancer can cause blood in urine, a GP should assess every episode to rule out important causes.
What tests will a GP do?: Urine tests, blood tests, and often referral for imaging — ultrasound or CT scan of kidneys and bladder. Men may have prostate examination; cystoscopy (camera into the bladder) may be recommended, especially over 45 or if tests are abnormal.
Is blood in urine a sign of cancer?: Bladder and kidney cancer can cause blood in urine — often without pain. It is not the most common cause, but early detection improves outcomes. This is why same-day GP assessment matters, especially for smokers and people over 45.

Sources

NHS — Blood in urine (haematuria)