Differential diagnosis of red urine (it does not always need to be blood)
Haematuria
Red blood cells in urine (macroscopic or microscopic)
Haemoglobinuria
From haemolysis. Classical red urine.
Positive urine dipstick
When urine spun in centrifuge the entire fluid will remain red – whereas whole red blood cells in urine will form a supernatant – ask the lab to spin when unsure!
Myoglobinuria
From muscle breakdown
Measure CK
When urine spun in centrifuge the entire fluid will remain red
Bilirubinuria
In obstructive jaundice
Does not occur in haemolyisis as this produced non-soluble unconjugated bilirubinaemia which is not soluble
Other
Beetroot
Rifampicin, nitrofurantoin, senna all change urine color
Porphyria
Types of haematuria
Two types
Macroscopic (visible)
Microscopic (non-visible)
There has been a shift towards using “visible” and “non-visible” haematuria although they mean the same thing
Macroscopic patients will tell you about it! They generally present earlier – this always needs investigation
Causes of haematuria (from kidney to urethral tip)
Kidney/Glomerular:
Glomerular
Thin basement membrane (TBM) in children – persistent microscopic haematuria
IgA nephropathy – transient macroscopic haematuria sometimes followed by persistent macrosopic haematuria
Alport’s syndrome – like TBM but associated with deafness, X-lined dominant in 85%, defect in IV collagen of basement membrane
Glomerulonephritis
Non-glomerular
Tumours (RCC, Wilm’s in children)
Nephrolithiasis
Infection – including renal TB
Polycystic kidneys
Trauma – take haematuria post trauma seriously!
Urethral stricture
Renal infarction/AVM/renal vein thrombosis
Sickle cell
Drugs (NSAIDs, anticoagulants)
Ureters
Stones
Tumours
Strictures
Urethritis
Bladder
Stones
Tumours
Transitional cell and squamous cell
Infections
Cyclophosphamide (haemorrhagic cystitis)
Need to heavily hydrate and give MESNA
Benign polyps
Schistosoma haematobium
Urethral
Benign prostatic hypertrophy
Prostatitis
Urethritis – take a sexual health history
Trauma
Transient or unknown source
Exercise induced
Menstruation
Post-coital
Over-anticoagulation (though still search for source in this case)
Functional
Non-specific viral illness
History in haematuria
Presenting complaint
How often, how much for how long?
Only associated with voiding? When in the stream?
Associated pain? Loin to groin? Suprapubic?
Associated symptoms
Any obvious masses?
Trauma?
Previous occurrences?
Systemic symptoms or “B type” symptoms: weight loss, fevers, night sweats
History of anticoagulation?
Recent infections (glomerulonephritis)?
Recent travel (Lake Malawi – schistosoma)?
Recent instrumentation?
Past medical history
Stone disease, cancer, recent anticoagulation, hypertension, diabetes
Cystoscopy is nearly always warranted: imaging does not allow for true luminal visualisation (as well as need for biopsies or ability to give treatment locally)
Renal biopsy
If glomerulonephritis suspected
Management of haematuria
Depends on cause
Urgent referral for:
Anyone with macroscopic haematuria
Anyone over 50 with persistent microscopic haematuria
Management algorithm for microscopic haematuria
Glomerular lesions are more likely if: proteinuria, red cells casts, renal impairment or hypertension.
If microscopic haematuria remains unexplained then as long as patient’s symptoms remain stable an annual review with a urine dip, blood pressure check and U&Es is reasonable (can be done by GP)
Some patients depending on risk will require annual cystoscopy