Causes of transient, non-visible/microscopic haematuria include:
- UTI/pyelonephritis
- menstrual period
- vigorous exercise
- sex
Causes of persistent, non-visible/microscopic haematuria include:
- renal stones
- prostatitis
- urethritis
- stones
- cancer
- benign prostatic hypertrophy
- IgA nephropathy
- benign familial haematuria
Macroscopic haematuria can be caused by:
- infection: UTI
- renal disease: renal papillary necrosis, IgA nephropathy, glomerulonephritis
- malignancy- although note just 4% of cases of bladder cancer will be asymptomatic except for haematuria
- renal stones
- prostatic hypertrophy
NICE guidelines demand urgent referral for:
- patients of any age with painless macroscopic haematuria
- patients aged 40+ with recurrent/persistent UTI and haematuria
- patients aged 50+ with unexplained microhaematuria
And as always consider whether the result could be spurious; false positive blood on dipstick can occur with:
- beetroot
- porphyria
- alkaptonuria
- rifampicin
Just a brief note at the end of this battle on benign familial haematuria. This accounts for around 25% of patients referred to nephrologists with microscopic haematuria. It is associated with the basement membrane being thinner than normal (<250nm compared with normal 450nm). Patients generally have a normal BP and normal renal function. They are however followed up as there is a small risk of renal failure.
Now on to a battle I fight daily in my current job... renal stones...
