Blood in Urine (Haematuria)

You may assume that a small amount of blood is harmless, especially if it disappears, or that blood always means cancer. Many causes are non cancerous, including infection and stones. However, visible blood in urine always needs prompt assessment, even when it occurs once or without pain.

Haematuria means blood in urine Haematuria means red blood cells are present in urine. It may be visible haematuria, where urine appears pink, red, brown or blood stained, or non visible haematuria, where blood is detected by urine testing but cannot be seen. Urgent GP or NHS 111 assessment is advised for visible blood, even when it is the first episode, there is only a small amount, no other symptoms are present, or you are uncertain whether it is blood. The urine may not appear bright red Blood can make urine appear pale pink, bright red, dark red, rust coloured, tea coloured, cola coloured, or brown. Colour does not reliably show where the bleeding started or how serious it is. A small quantity can change the colour of a large amount of urine. Not every red colour is urinary blood Urine may appear red or brown because of beetroot or strongly coloured foods, some medicines, menstrual or vaginal bleeding, bleeding from the rectum, muscle breakdown, or severe dehydration. A clinician may need a clean urine sample and examination to establish the source. Do not delay assessment because food or menstruation appears to provide a possible explanation when you are uncertain. Infection can cause blood A UTI may cause burning, frequency, urgency, lower abdominal pain, cloudy urine, fever, or visible blood. Blood associated with infection should be reassessed if it persists or returns after successful treatment. Repeatedly treating "UTI" without confirming resolution can delay investigation of another cause. Stones often cause pain and haematuria Kidney or ureteric stones may cause severe pain in the side or back, waves of pain travelling to the groin, nausea or vomiting, restlessness, urgency, or blood in urine. Some stones cause little pain. Fever or shivering with suspected stone disease raises concern about an infected obstructed urinary system and requires urgent hospital assessment. Bleeding may arise from the kidneys Kidney inflammation may allow blood and protein to enter urine. Possible features include tea or cola coloured urine, swelling around the eyes or ankles, reduced urine output, high blood pressure, headache, recent infection, or general illness. Glomerulonephritis is one possible cause and requires medical investigation. GP assessment is advised whenever blood is noticed in urine. The prostate can contribute If you have a prostate, blood may occur with prostate enlargement, prostatitis, recent prostate procedure, prostate cancer, or urinary retention. Visible haematuria still needs investigation rather than being automatically attributed to an enlarged prostate. Current guidance also advises considering PSA testing and prostate examination in people with relevant male reproductive organs who present with haematuria. Bladder and kidney cancer are important possible causes Visible blood may be the first symptom of bladder or kidney cancer. It may be painless, intermittent, present only once, or unaccompanied by other symptoms. Most people with haematuria will not necessarily have cancer. Urgent referral is used to identify or exclude serious disease promptly. A suspected cancer pathway referral is recommended for adults aged 45 or over with unexplained visible haematuria that occurs without UTI or persists or recurs after successful UTI treatment. Non visible blood has different referral criteria Non visible haematuria may be found during testing for another reason. It can occur with infection, kidney disease, stones, exercise, prostate disease, urinary cancer, or contamination from vaginal bleeding. A suspected bladder cancer referral is recommended for people aged 60 or over with unexplained non visible haematuria accompanied by dysuria or a raised white cell count. Other non visible haematuria is assessed according to kidney function, protein, blood pressure, symptoms and persistence. Age thresholds guide pathways, not concern The referral thresholds determine particular urgent cancer pathways. They do not mean that younger people can ignore visible blood, blood below the threshold is normal, cancer is confirmed above the threshold, or infection never needs follow up. Any visible haematuria requires prompt clinical assessment. Anticoagulants can increase bleeding Medicines such as warfarin, apixaban, rivaroxaban and other anticoagulants may make urinary bleeding more noticeable or prolonged. They do not establish the source. The urinary tract still requires assessment because infection, stones, tumours or kidney disease may be present. Do not stop an anticoagulant without urgent clinical advice. Sudden withdrawal may increase the risk of stroke or another serious clot. Exercise, trauma and procedures can cause bleeding Intense exercise may cause temporary blood in urine. However, you should not assume exercise is the explanation without assessment, particularly when blood is clearly visible, it recurs, you have pain, you are older, you have urinary symptoms, or you take anticoagulants. Persistent blood after exercise requires investigation. Haematuria may also occur after a blow to the back, abdomen or pelvis, a road collision, catheter insertion, cystoscopy, urinary surgery, or prostate biopsy. Follow the procedure specific advice. Heavy bleeding, inability to urinate, worsening pain or systemic illness requires urgent assessment. Clots can block urine flow Blood may clot inside the bladder or urethra. Possible features include passing clots, intermittent urine flow, increasing lower abdominal pain, urgency without urine output, inability to pass urine, or a swollen, painful lower abdomen. Clot retention is an emergency because the bladder becomes obstructed and bleeding may continue. Children require age appropriate assessment Blood in a child's urine may arise from UTI, stones, kidney inflammation, trauma, structural urinary conditions, or less commonly, a tumour. Visible haematuria is among symptoms increasing the likelihood of UTI in children. A child with blood and fever, loin pain, vomiting, reduced urine, swelling or marked illness needs urgent assessment. Visible blood in a baby should not be assumed to be caused by nappies, food or minor irritation without professional advice. Pregnancy requires prompt review If you are pregnant and see blood in urine, contact your maternity team, GP or NHS 111 promptly. Possible causes include UTI, kidney infection, stones, urinary irritation, or vaginal bleeding mistaken for haematuria. Vaginal bleeding during pregnancy follows a separate maternity assessment pathway. If you cannot tell where the blood came from, seek advice rather than trying to determine the source alone. Contacting a GP within 24 hours is advised for pain or blood during urination in pregnancy. Menstrual blood can contaminate a sample If a urine sample is collected during vaginal bleeding, the result may show blood that did not originate in the urinary tract. Tell the clinician about current bleeding. They may repeat the sample later, use a careful clean catch technique, or assess both urinary and gynaecological causes. Visible blood apparently mixed with urine should still be discussed promptly. Urine tests assess more than blood Testing may include dipstick, microscopy, culture, protein measurement, albumin to creatinine ratio, pregnancy testing where relevant, and cytology in selected specialist settings. Blood accompanied by significant protein may suggest a kidney filtering disorder rather than bleeding from the bladder. Blood tests and imaging assess effect and kidney function Possible blood tests include full blood count, kidney function, inflammatory markers, clotting tests, white cell count, and PSA after appropriate discussion where relevant. Kidney function assessment is specified within haematuria pathways, using raised white cell count as one factor in the non visible haematuria cancer referral criteria. Possible imaging includes ultrasound, CT scan, CT urography, or MRI in selected situations. The choice depends on age, kidney function, pregnancy, pain, suspected stones, cancer risk, and previous imaging. Cystoscopy examines the bladder A cystoscopy uses a thin camera passed through the urethra to inspect the bladder. It may identify bladder tumours, stones, inflammation, bleeding sites, or structural abnormalities. Local anaesthetic flexible cystoscopy is commonly used in haematuria assessment. A normal initial test may not complete the investigation Bleeding can be intermittent. Return for review if visible blood recurs, infection treatment finishes but blood remains, new pain or urinary symptoms develop, you pass clots, you lose weight, your urine output falls, or your health deteriorates. A normal urine sample between episodes does not prove that the previous visible bleeding was insignificant.

Haematuria is assessed through four questions: is blood genuinely coming from the urinary tract, is it visible or detected only on testing, is there infection, pain, obstruction or kidney disease, and does the pattern meet criteria for urgent specialist investigation. The amount and colour provide clues but do not identify the cause.