Haematuria

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Haematuria

Definition and Classification

Haematuria is the presence of blood (red blood cells) in the urine. It is classified into two main types:

Visible haematuria (VH) - macroscopic; blood is evident to the naked eye. This is a strong predictor of serious underlying pathology. Approximately 20-21% of patients with VH are found to have malignancy.

Non-visible haematuria (NVH) - microscopic or dipstick-detected. Defined as 3 or more (some sources say 5 or more) RBCs per high-power field on microscopy. The cancer detection rate for NVH is around 5%, significantly lower than VH.

30-60% of patients with NVH are found to have an underlying cause depending on age, risk factors, and type of investigation.
A few RBCs in urine is normal after vigorous exercise, sexual intercourse, or menstrual contamination, with an upper limit of 1 million RBCs per 24 hours considered normal.

- Bailey and Love's Short Practice of Surgery 28th Edition, p. 1537; Grainger & Allison's Diagnostic Radiology, p. 719

Pseudohaematuria

Before investigating, pseudohaematuria must be excluded. The urine may appear red without true haematuria due to:

Certain foods (e.g. beetroot)
Drugs: rifampicin, phenolphthalein, doxorubicin
Haemoglobinuria: haemolytic disorders (e.g. "march haematuria" in dehydrated soldiers after prolonged marching)
Myoglobinuria: rhabdomyolysis after crush injury or compartment syndrome
Porphyria: disordered haem production (urine turns brown/purple on sunlight exposure)

A clean midstream urine specimen with formal microscopy for RBCs is required to confirm true haematuria. Dipstick alone is not sufficient.

- Bailey and Love's, p. 1470; Campbell-Walsh Urology, p. 97

Timing of Haematuria in the Stream

The timing of blood in the urinary stream gives an anatomical clue:

Timing	Likely Origin
Initial (first part of stream)	Urethral or prostatic pathology
Throughout the entire stream	Bladder or upper urinary tract
Terminal (end of stream)	Bladder neck or prostatic urethra

Clot shape is also helpful: vermiform (worm-shaped) clots suggest upper tract origin; cuboid clots suggest bladder origin.

- Campbell-Walsh Urology, p. 104

Causes

A useful mnemonic is T-I-N (Trauma, Infection, Neoplasm) applied to each level of the urinary tract.

By anatomical level:

Kidney

Congenital: polycystic kidney disease, medullary sponge kidney
Traumatic: renal laceration/rupture
Inflammatory/Infective: acute nephritis, tuberculosis
Neoplastic: renal cell carcinoma, nephroblastoma (Wilms), urothelial tumour of renal pelvis, angioma
Others: renal calculi, renal infarction, papillary necrosis, vascular malformations, renal vein thrombosis
Nephrological: IgA nephropathy, glomerulonephritis, vasculitis, Henoch-Schonlein purpura, thin basement membrane disease, PUJ obstruction

Ureter

Calculus
Urothelial carcinoma (papilloma/carcinoma)
Stricture, benign conditions

Bladder

Traumatic: rupture
Inflammatory: bacterial cystitis, tuberculosis, schistosomiasis (bilharziasis), interstitial cystitis, radiation cystitis, ketamine cystitis, cyclophosphamide cystitis
Neoplastic: urothelial carcinoma (most common), squamous cell carcinoma, adenocarcinoma
Others: calculi

Prostate

Benign prostatic enlargement (BPH) - diagnosis of exclusion
Carcinoma of prostate
Prostatitis

Urethra

Traumatic: rupture
Inflammatory: acute urethritis
Neoplastic: transitional cell carcinoma
Urethral instrumentation

Diseases of Adjacent Viscera

Acute appendicitis, salpingitis, pelvic abscess spreading to ureter/bladder
Carcinoma of the rectum or cervix uteri infiltrating bladder

Systemic/General Causes

Blood disorders: purpura, sickle cell anaemia, haemophilia, scurvy, malaria, thrombophilia
Vascular: arterial emboli (from MI, subacute bacterial endocarditis)
Congestion: right heart failure, renal vein thrombosis
Collagen diseases / vasculitis
Anticoagulant therapy (haematuria should still be investigated even on anticoagulants)

Drug-Induced

Anticoagulants, hexamine, sulphonamides, salicylates (in high doses), alkylating chemotherapy agents, analgesic abuse

- S Das Manual on Clinical Surgery 13th Ed, p. 597; Bailey and Love's Table 83.15, p. 1537

Key Risk Factors for Malignancy

When assessing a patient with haematuria, the following increase the risk of underlying urological malignancy:

Age > 40 years
Smoking (most important modifiable risk factor for bladder cancer)
Occupational chemical exposure: benzene, aromatic amines (dye workers, rubber industry)
History of pelvic irradiation
Analgesic abuse
Alkylating chemotherapy (e.g. cyclophosphamide)
Chronic foreign bodies in urinary tract
Irritative voiding symptoms
Resistant/recurrent UTIs

The classic triad of loin pain + palpable loin mass + haematuria suggests renal cell carcinoma, but is present in fewer than 10% of cases.

- Campbell-Walsh Urology, p. 98-100; Bailey and Love's, p. 1469

Investigations

All patients (except young women with proven UTI):

Urine dipstick - screening tool; a positive result must be confirmed with microscopy
Urine microscopy (confirm RBCs, look for casts) and urine culture to exclude infection
Urine cytology - aids diagnosis of urothelial malignancy in higher-risk patients
Serum eGFR / renal function
PSA in men with a 10-15 year life expectancy
Digital rectal examination in men (assess prostate)

Imaging

CT Urogram (CTU) is the gold standard for upper tract evaluation. It detects urothelial tumours, stones, and renal lesions with high sensitivity.

Imaging algorithm by risk (Grainger & Allison):

Risk Group	Criteria	Investigation
Low risk	Microscopic or macroscopic haematuria, age < 40	Ultrasound (assess for medical renal disease)
Intermediate	Microscopic haematuria, age > 40 OR macroscopic age < 40	Unenhanced CT (best for renal stones)
High risk	Macroscopic haematuria, age > 40	CTU

Cystoscopy (flexible or rigid):

All patients with VH require lower tract evaluation with cystoscopy
NVH patients aged > 40 years should have flexible cystoscopy and renal tract imaging
NVH patients on three occasions that remains persistent warrants investigation

For NVH with proteinuria, red cell casts, raised creatinine, or hypertension - nephrology referral is indicated (glomerular cause likely).

- Grainger & Allison's Diagnostic Radiology, p. 719-721; Bailey and Love's, p. 1537

Summary of Key Points

Haematuria = VH (visible) or NVH (non-visible/microscopic)
Cancer detection: ~20% in VH vs ~5% in NVH
Always investigate even if the patient is on anticoagulants
Painless haematuria is most sinister - must exclude malignancy (bladder cancer is the most common cause of gross haematuria in patients > 50 years)
BPH is a diagnosis of exclusion as a cause of haematuria
Dipstick alone is insufficient - confirm with microscopy
Upper tract: CTU; Lower tract: flexible cystoscopy
If nephrological cause suspected (proteinuria, casts, hypertension), refer to nephrology

Note on recent evidence: The PubMed search (July 2026) did not return directly relevant systematic reviews or meta-analyses specifically on haematuria evaluation that would contradict the above textbook guidance. Current guidelines (AUA) continue to recommend the threshold of >3 RBCs/HPF on urinalysis as a trigger for urological evaluation.

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