Blood in Urine - Haematuria

Blood in urine must always be investigated - regardless of how much blood there is, how often it occurs, or whether it is associated with pain. A single episode of painless visible haematuria carries a cancer detection rate of approximately 10–25% and must never be dismissed as a urinary tract infection until proven otherwise. The commonest causes - kidney stones and infection - are benign, but the serious causes (bladder cancer, kidney cancer) may present identically and can only be excluded by proper investigation. The rule in urology is: haematuria is cancer until proven otherwise.

Visible haematuria (frank haematuria / macroscopic haematuria): blood can be seen in the urine - red, pink, or brown discolouration. This always requires urgent investigation regardless of cause. Non-visible haematuria (microscopic haematuria / dipstick haematuria): blood detected only by urine dipstick or microscopy, not seen by the naked eye. This is found in approximately 2–3% of the adult population. Persistent non-visible haematuria (detected on 2 of 3 specimens) also requires investigation, particularly in adults over 35 or those with risk factors.

A standard haematuria investigation includes: urine microscopy and culture (to exclude infection), urine cytology (looking for cancer cells shed from the urinary tract), flexible cystoscopy (camera examination of the bladder under local anaesthesia - the gold-standard test to exclude bladder cancer), and imaging - CT urogram (preferred) or CT KUB to assess kidneys and upper urinary tract for stones, masses, or abnormalities. Blood tests include creatinine, eGFR, and blood pressure. In younger patients with microscopic haematuria, renal causes (glomerulonephritis, IgA nephropathy) are also considered.

Yes - UTI is a common cause of haematuria, particularly in women. However, haematuria that persists after successful antibiotic treatment of a UTI must be investigated fully - it cannot be assumed the UTI was the cause. The combination of haematuria + UTI is particularly important to investigate in men (who rarely get uncomplicated UTIs) and in adults over 40 in either sex. In women under 40 with a clear UTI and no other risk factors, a single repeat urine test 6 weeks post-treatment is appropriate before deciding on further investigation.

Flexible cystoscopy is performed under local anaesthetic gel in the urethra. Most patients experience mild discomfort - pressure or a slight burning sensation - rather than significant pain. The procedure takes approximately 5–10 minutes. Modern flexible cystoscopes are very slim and the procedure is well-tolerated. Patients can drive home afterwards (no sedation is used) and return to normal activities the same day. Minor discomfort or slight blood in urine for 24–48 hours post-procedure is normal. Antibiotic prophylaxis is given.

A normal flexible cystoscopy means the bladder lining is normal - it excludes bladder cancer and other bladder pathology. However, haematuria can also originate from the kidney, ureter, or prostate, which are not fully assessed by cystoscopy alone. This is why imaging (CT urogram) is also required as part of the standard haematuria workup. In some patients with persistent microscopic haematuria despite normal cystoscopy and CT, renal causes (glomerulonephritis) are investigated - this requires blood pressure monitoring, proteinuria assessment, and sometimes renal biopsy under nephrology guidance.