Educational draft · awaiting clinical reviewThe full textbook explains uncertainty but does not replace live national or local guidance, specialist advice, or current prescribing information.
Haematuria: visible and non-visible
Renal · UK scope · Sources checked 27 Aug 2026 · Clinical review pending
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Time-critical presentation
Haemodynamic instability, ongoing heavy bleeding, clot retention, falling haemoglobin, sepsis with obstruction, solitary-kidney obstruction or rapidly progressive nephritic renal failure requires urgent hospital and urology or nephrology escalation. Resuscitation and drainage take priority over routine outpatient haematuria work-up.
Overview
Stabilise significant urinary bleeding, distinguish glomerular from urological sources and apply current cancer, infection, stone and nephrology pathways to visible or persistent non-visible haematuria.
Haematuria is a sign, not a diagnosis. Blood can originate from glomeruli, renal parenchyma, collecting system, ureter, bladder, prostate or urethra. The same patient may have more than one explanation, such as anticoagulation revealing a bladder tumour or UTI occurring alongside a stone.
The immediate branch is severity. Light stable bleeding without retention can usually enter an expedited outpatient pathway, while fresh blood with clots, poor drainage, anaemia or instability needs admission and source control. Septic hydronephrosis is particularly dangerous because antibiotics do not decompress an infected obstructed system.
The diagnostic branches are often simultaneous. Urology evaluates urothelial and structural causes through cystoscopy and upper-tract imaging selected by the haematuria service; nephrology evaluates glomerular disease through ACR/PCR, sediment, serology and sometimes biopsy. Age-based cancer referral should not cancel a renal assessment when protein and reduced function coexist.
Key points
First decide whether blood is visible or detected on reagent strip, painful or painless, and accompanied by clots, infection, obstruction or physiological instability.
Aetiology
01
Urothelial or renal malignancy
Bladder, upper-tract urothelial and renal tumours may bleed painlessly and intermittently; antithrombotic use can amplify bleeding without explaining away the underlying lesion.
02
Stone, infection or trauma
Calculi, urinary infection, instrumentation and injury disrupt urinary mucosa, often producing pain, dysuria, fever or a clear procedural context.
03
Glomerular disease
Inflammatory, immune-complex and inherited filtration-barrier disorders leak dysmorphic erythrocytes, usually alongside albuminuria, casts, hypertension or impaired kidney function.
04
Prostatic and lower-tract bleeding
Benign prostatic enlargement, urethral disease, cystitis and vascular mucosal lesions can produce visible or reagent-strip blood and sometimes obstructive clots.
Pathophysiology
1
Glomerular erythrocyte leakage
Capillary-wall defects force erythrocytes through the filtration barrier, distorting their shape and allowing red-cell casts to form within renal tubules.
2
Urinary-tract surface bleeding
Mucosal, tumour or vascular injury releases relatively intact erythrocytes into urine downstream of the glomerulus, sometimes producing visible clots.
3
Intermittent visible bleeding
Small lesions may bleed episodically as urine flow, infection, pressure or antithrombotic exposure changes, so a clear sample does not exclude important disease.
4
Clot-related obstruction
Heavy lower-tract bleeding permits coagulation within the bladder or ureter, impeding drainage and increasing pressure above the blockage.
Clinical features and red flags
Significant visible bleedingRed flag
Fresh dark-red urine, clots, inability to void, suprapubic pain, blocked catheter, haemoglobin fall or circulatory compromise indicates clinically important bleeding and possible clot retention.
Urothelial malignancy patternRed flag
Painless visible haematuria, smoking, aromatic-amine exposure, age, prior pelvic radiotherapy or cyclophosphamide increases concern. Intermittent bleeding is not reassuring.
Stone or upper infectionRed flag
Colicky flank-to-groin pain, restlessness, nausea and haematuria suggests ureteric stone; fever, rigors and loin tenderness suggests pyelonephritis. Their combination raises infected obstruction risk.
Glomerular haematuriaRed flag
Brown urine without clots, albuminuria, dysmorphic erythrocytes or red-cell casts, hypertension and oedema supports glomerular origin, especially with rash, arthritis or haemoptysis.
Persistent non-visible blood
Repeated reagent-strip blood after infection, menstruation and vigorous exercise have been addressed requires age-appropriate urology assessment plus blood pressure, eGFR and ACR evaluation.
Trauma or instrumentationRed flag
Recent catheterisation, biopsy, surgery or blunt injury changes the likely source. Blood at the urethral meatus or pelvic fracture signs require senior urology input before blind catheterisation.
Investigations
01Reagent-strip urinalysis and fresh microscopyFirst step
Why
Confirm haem pigment, detect infection and protein, and assess renal sediment when indicated.
Interpretation and limitations
Dysmorphic cells and casts support glomerular origin; clots and isomorphic cells favour post-glomerular bleeding. A positive blood pad with no cells suggests haemoglobin or myoglobin.
02Urine culture
Why
Confirm bacterial infection and guide antibiotics when symptoms or pyuria are present.
Interpretation and limitations
Treat genuine infection, then ensure visible haematuria resolves. Persistence or recurrence after successful treatment enters the NICE suspected-cancer pathway at the qualifying age.
03FBC, creatinine, electrolytes and coagulation
Why
Measure blood loss, renal impact and correctable haemostatic contributors.
Interpretation and limitations
A stable initial haemoglobin can precede a later fall after acute bleeding. Review INR or anticoagulant timing, but reverse therapy only through a severity- and indication-specific plan.
04Urine ACR or PCR
Why
Quantify accompanying protein and identify renal parenchymal risk.
Interpretation and limitations
Albuminuria with haematuria increases the likelihood of glomerular disease and can meet nephrology referral criteria even while urological cancer evaluation proceeds.
Differential diagnosis
01
Pigmenturia
Myoglobin or free haemoglobin makes dipstick blood positive with few erythrocytes on microscopy; muscle injury or haemolysis then provides the discriminating context.
02
Food or medicine discolouration
Beetroot, rifampicin and other pigments can redden urine without a positive haem reaction or urinary erythrocytes.
03
Menstrual or genital contamination
Bleeding outside the urinary tract may contaminate a sample; careful history and a correctly timed clean-catch specimen help localise the source.
04
Glomerular versus urological bleeding
Dysmorphic cells, casts and albuminuria favour glomerular disease, whereas clots, irritative symptoms and a normal renal sediment favour a urological source.
05
Haemorrhagic infection versus malignancy
Culture-supported urinary symptoms favour infection, but persistent or recurrent blood after treatment still requires age- and risk-appropriate malignancy assessment.
Management
01Acute bleedingStabilise and restore drainageFirst stepClots, retention, catheter blockage, haemoglobin fall, heavy ongoing haematuria or instability.+
1Perform ABCDE, obtain IV access, FBC, group and save/crossmatch, renal profile and coagulation, and review antithrombotic indication with senior help.
2If clot retention is present and urethral injury is not suspected, involve urology for an appropriate large-bore three-way catheter, manual washout and continuous irrigation under local practice.
3EscalationEscalate persistent bleeding for cystoscopic clot evacuation or haemostatic intervention; treat sepsis and decompress an obstructed upper tract urgently when present.
02Visible haematuriaApply cancer criteria after acute safetyVisible urinary blood without current admission criteria or after acute bleeding has settled.+
1
Complications
01
Clot retention and obstructive AKI
Accumulated bladder clots can cause painful retention, hydronephrosis and acute kidney injury, particularly when outflow is already narrowed.
02
Anaemia and circulatory compromise
Sustained or brisk urinary bleeding can reduce haemoglobin and, rarely, circulating volume, especially with anticoagulation or tumour-related haemorrhage.
03
Delayed underlying-disease diagnosis
Attributing blood to infection or antithrombotic therapy can postpone detection of malignancy, stones or progressive glomerulonephritis and worsen their eventual consequences.
Monitoring and follow-up
During acute visible bleeding, chart urine colour and clots, catheter drainage and irrigation balance, haemodynamics, haemoglobin, creatinine and transfusion need.
After treating UTI, confirm whether visible haematuria fully resolves and document referral if it persists or recurs rather than prescribing another empirical course.
For persistent non-visible haematuria, monitor blood pressure, eGFR and ACR at an individualised interval and re-refer if protein or function worsens.
Following negative urology evaluation, safety-net recurrent visible blood, new urinary symptoms, constitutional features or flank pain and retain renal surveillance where indicated.
If antithrombotic treatment is interrupted, record the exact restart decision, responsible clinician and renal-dose reassessment to avoid accidental permanent omission.
Special situations
Clots imply post-glomerular blood
Glomerular bleeding is dispersed through urine and rarely forms visible clots. Clots point toward collecting-system or lower-tract bleeding and create a separate retention risk.
Infection needs a second look
A positive culture may be genuine yet coexist with malignancy. NICE specifically uses persistence or recurrence after successful treatment as a visible-haematuria referral trigger.
Two specialties can be right
An older patient with visible blood, raised ACR and declining eGFR may need cystoscopy and a nephrology work-up in parallel rather than competing referrals.
Bleeding can be intermittent
A normal urine sample between episodes does not erase witnessed visible haematuria. Document the history and apply the appropriate referral criteria.
Contrast choice is contextual
CT urography answers a different question from non-contrast CT KUB or ultrasound. The haematuria service selects imaging from cancer risk and renal safety, not a one-scan-fits-all rule.
Common pitfalls
01
Attributing painless visible haematuria to anticoagulation without investigating the urinary tract.
02
Treating culture-positive urine and failing to confirm that visible bleeding resolves.
03
Sending a patient with clot retention home because the first haemoglobin is normal.
04
Forcing a urethral catheter when pelvic trauma or urethral injury is suspected.
05
Pursuing only urological cancer tests despite heavy albuminuria and an active renal sediment.
06
Using non-contrast stone CT as the automatic imaging study for every haematuria presentation.
Practice
Two practice questions
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Question 1 of 2
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RenalOriginal SBA
Visible blood after UTI
A fifty-seven-year-old had visible haematuria during a culture-proven UTI. Symptoms resolve with antibiotics, but visible blood recurs two weeks later. What is the best next step?
Sources and review status4 sources · checked 27 Aug 2026 · clinical review pending+
Sources
Sources and review status
National guidance is shown before implementation-dependent detail. Typical adult dose examples remain subject to patient factors, contraindications and the live BNF or specialist protocol. Source check completed 27 Aug 2026; clinical approval remains outstanding.
Confirm that red urine is blood: beetroot, rifampicin, porphyria, haemoglobin and myoglobin can change colour or the dipstick result. Menstrual or genital bleeding may contaminate a sample.
Painless visible haematuria is a urinary malignancy signal until appropriately investigated. Anticoagulants and antiplatelets can increase bleeding but do not remove cancer or stone risk.
NICE recommends a suspected-cancer referral for people aged 45 or over with unexplained visible haematuria without UTI, or haematuria persisting or recurring after successful UTI treatment.
For bladder cancer, NICE also recommends urgent referral in people aged 60 or over with unexplained non-visible haematuria plus dysuria or a raised peripheral white-cell count.
Clots usually point to non-glomerular bleeding and can obstruct the bladder outlet. A three-way catheter and irrigation require competent urological technique and caution if urethral injury is possible.
Painful haematuria suggests stones, infection, trauma or retention, but pain does not exclude malignancy and absence of haematuria does not exclude a CT-proven stone.
Smoky or cola urine, dysmorphic red cells, red-cell casts, proteinuria, hypertension, oedema and impaired function support glomerular bleeding and a parallel nephrology pathway.
Do not use urine microscopy to count red cells as the sole confirmation of non-visible haematuria in adults when NICE recommends reagent-strip detection; microscopy remains valuable for renal localisation.
A negative initial urological investigation needs explicit safety-netting and renal surveillance when haematuria, albuminuria, hypertension or declining eGFR persists.
05Cystoscopy
Why
Inspect urethra and bladder for tumour, stone, inflammation or bleeding source.
Interpretation and limitations
Performed by the haematuria/urology service according to risk and fitness. Normal cystoscopy does not assess renal glomeruli or fully replace appropriate upper-tract imaging.
06Upper urinary tract imaging
Why
Assess kidneys and ureters for mass, stone, obstruction or urothelial lesion.
Interpretation and limitations
CT urography, ultrasound or another modality is selected from age, cancer risk, renal function, pregnancy and local protocol. Non-contrast CT is used for acute adult renal colic, not as a universal haematuria scan.
Confirm urinary source, examine, culture when infection is plausible and check FBC, renal function, ACR and smoking/occupational risk.
2Refer through the current NICE suspected-cancer route for qualifying unexplained visible haematuria or persistence/recurrence after treated UTI; do not exclude because anticoagulated.
3The haematuria service coordinates cystoscopy and upper-tract imaging. Provide clear reattendance advice for clots, retention, fever, pain or heavier bleeding.
03Non-visible haematuriaConfirm persistence and dual-localiseIncidental reagent-strip blood in a clinically stable patient.+
1Address menstruation, exercise and infection, then repeat at the recommended interval; quantify ACR, measure blood pressure and retrieve eGFR trend.
2Use NICE cancer referral criteria where age and associated dysuria or raised white count qualify, and use urology advice for persistent unexplained bleeding or risk factors.
3Discuss with nephrology when proteinuria, renal impairment, hypertension, casts or systemic features suggest renal origin, continuing longer-term monitoring after a negative work-up.
Key medicines and prescribing safety2 treatments · regimens, roles and cautions+
Balances haemostasis against stroke, valve or venous thromboembolism risk during significant haematuria.
Anticoagulant or antiplatelet review
Continue, interrupt or reverse only after assessing bleed severity, timing, renal clearance and the original thrombotic indication with the relevant senior pathway.
Do not assume the medicine is the underlying diagnosis. Unplanned cessation may cause thrombosis, while renal impairment can prolong exposure to some agents.
Treats infection contributing to haematuria while ensuring resolution is documented and structural causes are still considered.
Antibiotic for culture-supported urinary infection
Choose from current local and NICE guidance using infection site, sepsis severity, prior cultures, allergy, pregnancy and renal function.
Antibiotics do not relieve obstruction or clot retention. Persistent visible haematuria after successful treatment requires cancer-pathway assessment where criteria are met.