Urine
Blood in urine
Blood in the urine should always be checked by a doctor, as while many causes are treatable infections or stones, it can occasionally be the first sign of a more serious problem.
Education and reference only. This explains the common causes of blood in urine and the warning signs that need urgent help, in plain language — it is not a diagnosis or a substitute for advice from a clinician. If you feel very unwell or are worried, seek medical help.
Quick answer
What is blood in urine?
Seeing blood in your urine, known medically as haematuria, can be alarming. The urine may look pink, red or brown, or blood may only show up on a urine test done by a doctor.
- Get urgent help: Being unable to pass urine, or passing blood clots that block the flow, needs urgent same-day assessment. Blood in the urine with severe pain in the back or side, a high temperature, shivering or feeling very unwell can mean a serious infection — seek urgent care.
- Self-care: There is no safe home remedy for blood in the urine, because it always needs to be investigated to find the cause.
About blood in urine
Seeing blood in your urine, known medically as haematuria, can be alarming. The urine may look pink, red or brown, or blood may only show up on a urine test done by a doctor. Many causes are relatively straightforward, such as a urinary infection or a kidney stone, and these can be treated. However, visible blood in the urine can also be the first sign of a problem in the bladder, kidneys or prostate, including cancer, which is why it is important to have it investigated even if it only happens once and then settles. Certain foods, such as beetroot, and some medicines can colour the urine without it being blood, but you should never assume this is the explanation. The key message is simple: blood in the urine is something to get checked promptly rather than wait and see.
When to get help
Call 999 or go to A&E if blood in urine comes with any of these warning signs:
- Being unable to pass urine, or passing blood clots that block the flow, needs urgent same-day assessment.
- Blood in the urine with severe pain in the back or side, a high temperature, shivering or feeling very unwell can mean a serious infection — seek urgent care.
- Heavy bleeding, feeling faint, or a rapidly worsening condition warrants emergency assessment.
- Visible blood in the urine at any time should always be checked promptly, as it can be a sign of bladder or kidney cancer even if it settles.
- Blood in the urine after a significant injury to the back, side or abdomen needs urgent assessment.
When to see a doctor
Always see a doctor if you notice blood in your urine, even once and even if it then clears up, because the cause needs to be identified. Make an appointment promptly rather than waiting to see if it returns. Mention any other symptoms such as pain, burning, fever, or changes in how often you pass urine, and tell the doctor about any medicines you take that thin the blood. If you have previously been investigated and a cause was found, but the bleeding changes or new symptoms develop, get checked again. Early assessment gives the best chance of treating any underlying problem effectively.
Not sure how urgent it is? It is always OK to call NHS 111 for advice, day or night.
What can cause it
Common causes of blood in urine
Blood in urine has many possible causes. Each links to a full, plain-language guide to that condition — what it is, how it's treated and when to seek help.
What helps
Self-care and what you can do
There is no safe home remedy for blood in the urine, because it always needs to be investigated to find the cause. While arranging to be seen, drinking plenty of water can help dilute the urine and is generally sensible if you have a suspected infection. Make a note of when you noticed the blood, whether it was throughout the stream or only at the start or end, and whether you had any other symptoms such as pain or fever, as this information helps the doctor. Avoid assuming that something you ate is responsible. Do not delay seeking assessment even if the bleeding stops on its own.
Answers
Blood in urine: frequently asked questions
Is blood in urine always serious?
Not always — common causes include urinary infections and kidney stones, which are treatable. However, because it can occasionally signal a bladder, kidney or prostate problem, it should always be checked by a doctor.
Should I worry if the blood only appeared once?
Yes, it should still be investigated. Visible blood in the urine warrants assessment even if it happens only once and then stops, as some serious causes can bleed intermittently.
Could something I ate cause red urine?
Foods such as beetroot and some medicines can turn urine pink or red without it being blood. However, you should never assume this is the cause — see a doctor to be sure.
What tests might the doctor do?
A doctor will usually test a urine sample and may arrange blood tests, scans, or a look inside the bladder with a small camera, depending on your symptoms and risk factors. The aim is to find the cause and reassure or treat as needed.
Sources
Where this is drawn from
- NICE CKS: Haematuria.
- Kidney Care UK
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