Haematuria

Blood may originate from the kidney or the collecting system. The initial determination of microscopic haematuria should be based on microscopic examination of urinary sediment from a freshly voided, clean-catch, midstream urine specimen.¹

• The prevalence of asymptomatic microscopic haematuria varies from 0.19 percent to as high as 21 percent.¹
• In one study of 1,000 patients with haematuria (but no proteinuria), the common causes of haematuria were inflammatory conditions of the urethra and prostate, benign prostatic hypertrophy, cystitis, transitional carcinoma of the bladder, and stones in the renal pelvis or ureter. 8% had some form of renal tract malignancy.²
• In a screening study of men aged over 50 years, pathological conditions were found in 31 out of 44 who had haematuria at least once on serial testing. One-third of the 44 had either cancer of the urinary tract or other conditions requiring immediate treatment.

Common causes include urinary tract infection, bladder tumours, urinary tract stones, urethritis, benign prostatic hypertrophy and prostate cancer.

• Infection: cystitis, tuberculosis, prostatitis, urethritis, schistosomiasis, infective endocarditis.
• Tumour: renal carcinoma, Wilms' tumour, carcinoma of the bladder, prostate or urethra.
• Trauma: renal tract trauma due to accidents, catheter or foreign body, prolonged severe exercise, rapid emptying of an overdistended bladder (e.g. after catheterisation for acute retention).
• Inflammation: glomerulonephritis, Henoch-Schonlein purpura, IgA nephropathy, Goodpasture's syndrome, polyarteritis, post-irradiation.
• Structural: calculi (renal, bladder, ureteric), simple cysts, polycystic renal disease, congenital vascular anomalies.
• Haematological: sickle cell disease, coagulation disorders, anticoagulation therapy.
• Surgery: invasive procedures to the prostate or bladder.
• Toxins: sulphonamides, cyclophosphamide, non-steroidal anti-inflammatory drugs.
• Others: genital bleeding, including child abuse; menstruation; factitious (including Munchausen by proxy).

Other causes of red or dark urine:

• Haemoglobinuria: dipstick positive but no red cells on microscopy
• Myoglobinuria
• Food, e.g. beetroot
• Drugs, e.g. rifampicin, nitrofurantoin, senna
• Porphyria: urine darkens on standing
• Bilirubinuria: obstructive biliary disease

• Take a full urological history and include palpation of the abdomen and blood pressure.
• Features suggesting a renal cause include hypertension, altered renal function tests, proteinuria, known previous renal problems, renal mass and glomerular red cells in urine.
• Haematuria without proteinuria does not necessarily indicate a non-glomerular origin as glomerular bleeding is not necessarily accompanied by proteinuria.³

• All children with haematuria should be referred.
• All definite haematuria, whether macroscopic or microscopic, requires investigation to exclude serious underlying conditions, especially urinary tract neoplasm.⁴
• Patients on anticoagulants should also be investigated. Anticoagulants are more likely to provoke rather than be the cause of haematuria.
• Check full blood count (anaemia), renal function and clotting screen
• Urinary microscopy and culture
• Urine red cell morphology: dysmorphic erythrocytes suggest a renal origin
• Cytological examination of urine⁵
• Ultrasound of renal tract: if urinalysis does not explain the findings. Ultrasound is as sensitive as intravenous urography and more cost-effective.⁶ A plain film of the abdomen should also be obtained, mainly to rule out urinary calculi.
• Cystoscopy: important in younger as well as older patients. One study looking at almost 2,000 patients with haematuria found bladder cancer in 7 patients younger than 40 years.⁷
• Renal biopsy
• Intravenous urography is indicated if urinary tract stones are suspected or if ultrasound, abdominal x-ray and cystoscopy are negative.
• Renal angiography, CT scanning or biopsy are indicated in specific circumstances.

If a definite diagnosis cannot be made, investigations should be repeated whenever gross haematuria occurs or after 4-6 months. Occult cancer will usually become evident within one year.

The NICE Cancer Referral Guidelines recommend urgent referral for:⁸

• Patients of any age with painless macroscopic haematuria.
• Aged 40 years and older who present with recurrent or persistent urinary tract infection associated with haematuria.
• Aged 50 years and older who are found to have unexplained microscopic haematuria.
• With an abdominal mass identified clinically or on imaging that is thought to arise from the urinary tract.