Key distinguishing features of the most common diagnoses
|Poor Urinary Stream||No||Possible||Possible||No||Yes|
Likely:Urinalysis, MSU, FBC, U&E, ACR/PCR.
Possible:PSA, ultrasound, plain abdominal X-ray, cystoscopy.
Small Print:Urethral swab, CT scan, urine cytology, renal biopsy, angiography.
- Urinalysis: Pus cells and nitrite in UTI. Pus cells alone in urethritis, TB and bladder tumour. Presence of protein suggests renal disease.
- Urine microscopy and culture to establish pathogen in infection. May show casts in renal disease.
- FBC and U&E help establish basic renal function and any associated anaemia or leucocytosis; consider PSA – usually elevated in prostatic carcinoma.
- ACR/PCR: To quantify any proteinuria.
- Urethral swabs if urethritis (best done at GUM clinic).
- If painless haematuria, ultrasound may show renal tumour or polycystic kidneys; CT may be more useful.
- Specialist investigations include renal imaging, cystoscopy, urinary cytology, renal biopsy and angiography.
- Microscopic haematuria in an asymptomatic menstruating woman can be ignored temporarily; repeat the urinalysis at mid-cycle.
- Remember that there are other less common causes of spurious haematuria – sometimes the blood may be coming from the rectum or vagina. Assess each case carefully and be prepared to rethink if symptoms persist but urological investigations prove negative.
- Some food pigments, beetroot and certain drugs (e.g. nitrofurantoin) can colour the urine red – confirm haematuria with urinalysis to save the patient unnecessary tests.
- Painless frank haematuria is an ominous sign indicating possible malignancy.
- Beware of recent onset of recurrent cystitis with haematuria in the elderly. The underlying cause may be a bladder tumour, especially if the haematuria (micro- or macroscopic) does not settle with treatment of the infection.
- Renal tumours can sometimes present with renal colic, as blood clots in the ureters mimic the effects of stones. A useful clue is that the bleeding may precede the pain.
- Haematuria requires emergency admission if there is significant blood loss or clot retention.
- Remember the possibility of chronic ketamine abuse in young people.