Blood in Urine (Haematuria) — Causes, Symptoms, Diagnosis & Treatment Guide — Symptoms, Causes & Treatment | MyMedicPlus

Haematuria is the presence of blood in the urine. It is classified as visible (macroscopic haematuria — urine appears red, pink, or brown, visible to the naked eye) or non-visible (microscopic haematuria — dipstick-positive or laboratory-confirmed; defined as 3 or more red blood cells per high-power field on urine microscopy). Haematuria is always a symptom requiring investigation in adults — it is never normal. It is further divided by anatomical origin: glomerular (from kidneys — RBC casts, dysmorphic red cells, proteinuria), upper urinary tract (kidneys, ureters), or lower urinary tract (bladder, urethra, prostate). Causes range from benign (UTI, kidney stones, vigorous exercise) to serious (bladder, kidney, or prostate cancer). Visible haematuria in any adult is assumed to be due to urological malignancy until proven otherwise and warrants urgent 2-week wait cancer referral. NICE recommends urgent assessment for all visible haematuria and unexplained non-visible haematuria in adults over 60.

Lower urinary tract causes (most common): urinary tract infection (UTI — most common cause of haematuria in women; dysuria, frequency, and offensive-smelling urine); bladder cancer (most common cause of painless visible haematuria in adults over 50 — transitional cell carcinoma; risk factors: smoking, age, occupational carcinogen exposure); urethritis; benign prostatic hyperplasia (BPH) in men; bladder polyps or stones; catheter trauma. Upper urinary tract causes: nephrolithiasis (kidney stones — commonly associated with flank pain, loin-to-groin radiation, nausea); renal cell carcinoma; urothelial carcinoma of the renal pelvis or ureter; glomerulonephritis — IgA nephropathy (Berger's disease — most common glomerular cause globally, often follows upper respiratory tract infection), thin basement membrane disease, hereditary nephritis (Alport syndrome), post-streptococcal glomerulonephritis. Other: anticoagulant therapy (warfarin, direct oral anticoagulants — haematuria on anticoagulation still requires full investigation; anticoagulation does not cause haematuria — it unmasks underlying pathology), inherited conditions (sickle cell, polycystic kidney disease), vigorous exercise (benign — self-resolving), trauma, renal papillary necrosis. Pseudo-haematuria: red/orange urine from beetroot, rifampicin, doxorubicin, myoglobinuria — dipstick and microscopy distinguish.

Visible haematuria: urine appears red (fresh blood), pink (dilute), or brown/cola-coloured (old blood). Clots may be passed — clot retention can cause acute urinary retention (emergency). Symptoms suggesting the cause: dysuria, frequency, urgency (UTI — lower tract); fever and loin pain (pyelonephritis — upper tract); severe loin-to-groin colicky pain (renal colic — kidney stone); weight loss, anorexia, night sweats (malignancy); recurrent macroscopic haematuria following upper respiratory tract infection (IgA nephropathy); generalised oedema and hypertension (nephrotic/nephritic syndrome). Painless visible haematuria — the most important red flag symptom: absence of pain does not make malignancy less likely; if anything, painless haematuria is more suspicious for bladder or kidney cancer. Non-visible haematuria: usually asymptomatic — discovered on routine urinalysis or pre-employment health check.

All adults with visible haematuria should be referred urgently (2-week wait pathway, NICE NG12). Dipstick urinalysis: detects haemoglobin (both visible and non-visible); positive dipstick must be confirmed by urine microscopy (avoid false positives from myoglobinuria, menstruation, dehydration). Urine microscopy and culture: counts red blood cells, detects RBC casts (glomerulonephritis indicator), and excludes infection. CT urogram (CTU — computed tomography urography): gold standard imaging investigation — identifies renal masses, upper tract urothelial tumours, kidney stones, and structural abnormalities of the entire urinary tract; preferred over ultrasound which misses urothelial tumours. Flexible cystoscopy: direct visualisation of the bladder mucosa under local anaesthesia in clinic — gold standard for bladder cancer detection and biopsy. Urine cytology: detects exfoliated malignant cells — moderate sensitivity for high-grade bladder cancer; cannot exclude malignancy if negative. Renal biopsy: when glomerulonephritis is suspected (non-visible haematuria + proteinuria, dysmorphic RBCs, RBC casts, hypertension, abnormal renal function). PSA in men over 50. NICE 2-week wait referral criteria: visible haematuria at any age; non-visible haematuria with dysuria or raised WBC in adults 60 or above; unexplained non-visible haematuria in adults 60 or above; recurrent or persistent unexplained haematuria.

Treatment depends entirely on the underlying cause. Urinary tract infection: antibiotic therapy (trimethoprim, nitrofurantoin, cefalexin — guided by local resistance patterns and urine culture); haematuria resolves with treatment. Renal colic and kidney stones: analgesia (diclofenac NSAIDs first-line, opioids if required); alpha-blocker (tamsulosin) aids passage of stones under 10 mm; stones above 5 mm unlikely to pass spontaneously — shock wave lithotripsy (ESWL), ureteroscopy with laser fragmentation, or percutaneous nephrolithotomy (PCNL) for large stones. Bladder cancer: transurethral resection of bladder tumour (TURBT) for staging and initial treatment; intravesical BCG immunotherapy reduces recurrence in non-muscle-invasive bladder cancer; muscle-invasive bladder cancer: radical cystectomy with neoadjuvant cisplatin-based chemotherapy. Renal cell carcinoma: partial or radical nephrectomy (surgical); targeted therapy (sunitinib, cabozantinib) or immunotherapy (nivolumab) for metastatic disease. IgA nephropathy: ACE inhibitor or ARB (reduces proteinuria and slows progression); sparsentan (approved 2023); immunosuppression for active inflammation; SGLT2 inhibitors for additional renoprotection. Clot retention: urethral catheter and bladder irrigation.

Blood in the urine (haematuria) is a symptom — the underlying causes determine complications rather than the haematuria itself. Most seriously, haematuria is the most common presenting symptom of bladder cancer (occurring in 80-85% of cases) — delays in investigation of even single episodes of painless macroscopic haematuria allow cancer to progress to a higher stage, significantly worsening prognosis; bladder cancer detected at non-muscle-invasive stage has a 5-year survival above 80%, versus below 10% for metastatic disease. Renal cell carcinoma presents with haematuria in approximately 40% of cases. Chronic microscopic haematuria from IgA nephropathy (Berger's disease), the most common glomerulonephritis globally, can progress to end-stage renal disease in 20-40% of patients over 20-30 years. Renal papillary necrosis — complicating diabetes, analgesic nephropathy, or sickle cell disease — causes haematuria, renal colic, and progressive renal impairment. Heavy haematuria causing large clots (clot retention) can obstruct urine outflow — a urological emergency requiring bladder irrigation and catheterisation. Significant haematuria causing iron-deficiency anaemia and haemodynamic compromise requires urgent urological assessment. Anticoagulant-associated haematuria (warfarin, DOAC therapy) may indicate a coexisting urological pathology — investigation should proceed regardless of anticoagulation.

Stop smoking: smoking is the single most important modifiable risk factor for bladder cancer — approximately 50% of bladder cancer cases in the UK are attributable to tobacco use. Adequate hydration: reduces UTI risk and dilutes potential urinary carcinogens. Occupational exposure reduction: rubber, dye, and chemical industries carry elevated bladder cancer risk from aromatic amine carcinogens (2-naphthylamine, benzidine) — regulatory standards and personal protective equipment are essential. Regular blood pressure monitoring and renal function tests for patients with IgA nephropathy or other glomerular disease to detect progression early. Prompt treatment of UTIs to prevent ascending infection and pyelonephritis. Avoid excessive analgesic use (phenacetin, NSAIDs long-term) — analgesic nephropathy causes renal papillary necrosis and haematuria.

Seek urgent medical assessment — same day or next day — for any episode of visible blood in the urine in adults. This includes even a single episode of painless visible haematuria, which is a red flag for urological malignancy and must not be attributed to benign causes without full investigation. Go to A&E immediately for: visible haematuria with clots causing difficulty urinating (clot retention), inability to pass urine (acute urinary retention), severe flank or loin pain, or fever with rigors (signs of urosepsis from pyelonephritis). Non-visible haematuria found on urinalysis in adults over 60 warrants GP assessment and urology referral. Do not assume haematuria is due to anticoagulant medication — haematuria on anticoagulation always requires investigation as for patients not taking anticoagulants.