Finding blood in your urine can be very frightening and must be investigated by a doctor, but it's not usually a sign of anything life-threatening.
If you notice bright red blood in your urine, or if your urine has turned red or brown because it has blood in it, see your GP.
Sometimes, urine may contain only a small amount of blood invisible to the naked eye and is only apparent when a urine test is carried out for something else. This still needs to be investigated by your doctor, as healthy urine should not contain any detectable amounts of blood.
The medical name for blood in the urine is haematuria. If blood in the urine is obvious with the naked eye, it is called "macroscopic", or "visible haematuria". If the blood can only be detected with laboratory testing, it is called "microscopic", or "non-visible".
The blood will have come from somewhere within the urinary tract – the kidneys, bladder or the tubes that urine passes through. It is often the result of a urinary tract infection (UTI), such as cystitis.
This page outlines the most common reasons for blood in the urine, to give you an idea of what may be causing the problem. However, this guide should not be used to self-diagnose your condition, and it's important to see your GP for a proper diagnosis.
Is there definitely blood in your urine?
Before you read on, it's worth considering whether you have recently eaten beetroot, as this can colour the urine pink and cause unnecessary alarm. Some medicines, such as the antibiotics nitrofurantoin and rifampicin, can also turn your urine red or brown.
Check that the blood is actually coming from your urine and not your vagina (if you're a woman) or back passage.
Common causes of blood in urine
a bladder infection (such as cystitis) – which typically also causes a burning pain when you urinate
a kidney infection – which may also cause a high temperature and pain in the side of your tummy
kidney stones – which may be painless, but can sometimes block one of the tubes coming from your kidneys and cause severe tummy pain
urethritis – inflammation of the tube that carries urine out of the body (urethra); it's often caused by a sexually transmitted infection (STI) such as chlamydia
an enlarged prostate gland – this is a common condition in older men and nothing to do with prostate cancer; an enlarged prostate gland will press on the bladder and may also cause problems such as difficulty urinating and a frequent need to urinate
bladder cancer – this usually affects adults aged over 50 and can also cause you to urinate more often and more urgently, as well as pain when urinating
kidney cancer – this also usually affects adults aged over 50, and can cause persistent pain below your ribs and a lump in your tummy
prostate cancer – this is usually only seen in men aged over 50 and usually progresses very slowly; other symptoms can include needing to urinate more frequently and urgently, and difficulty emptying your bladder
Seeing your GP
Your GP will ask about your symptoms and carry out a physical examination to help determine the cause of the blood in your urine. For men, this may include a rectal examination and women may have a vaginal examination.
They will also arrange blood/and or urine tests to look for signs of an infection. If they think that an infection is likely, they may prescribe some antibiotics before you get your results and will refer you to a specialist if your test results later show you don't have an infection.
In some cases, your GP may recommend keeping an eye on your symptoms to see if they get better on their own over time.
Referral to a specialist
Your GP should refer you urgently to a specialist if any of the following apply:
you have visible blood in your urine and no pain, and tests show there is no infection
you are 40 or over and keep getting UTIs and blood in your urine
you are 50 or over and a urine test picks up unexplained non-visible blood in your urine
you have a lump in your tummy (a possible tumour) that was picked up during physical examination by your doctor or during a scan
non-visible haematuria is picked up during a test, particularly if there is also protein found in the urine
You will be referred to a hospital urology or nephrology department, or a specialist haematuria clinic, for further tests to identify the cause of your symptoms.
These tests may include more blood and urine tests, an ultrasound scan, an X-ray and a cystoscopy. This is a procedure used to examine the inside of the bladder, using an instrument called a cystoscope.