Blood in Urine

Differential Diagnosis

Occasional Diagnoses

  • Jogging and Hard Exercise
  • Renal Carcinoma
  • Chronic Interstitial Cystitis
  • Anticoagulant Therapy
  • Nephritis/Glomerulonephritis

Rare Diagnoses

  • Renal Tuberculosis
  • Polycystic Kidney Disease
  • Blood Dyscrasias: Thrombocytopenia, Haemophilia, Sickle-Cell Disease
  • Infective Endocarditis
  • Schistosomiasis (Common Abroad)
  • Trauma
  • Ketamine-Associated Ulcerative Cystitis

Ready Reckoner

Key distinguishing features of the most common diagnoses

UTIBladder TumourStonesUrethritisProstate
Frank BloodPossiblePossiblePossibleNoPossible
Urethral DischargeNoNoNoYesNo
Poor Urinary StreamNoPossiblePossibleNoYes
Loin PainPossibleNoPossibleNoNo

Possible Investigations

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.

Top Tips

  • 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.

Red Flags

  • 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.
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