Sandbox:Hematuria overview

Hematuria is the presence of blood cells in the urine. Gross hematuria is when blood is visible in the urine. Microscopic hematuria is defined as 3 or more red blood cells per high-powered field in a properly collected urine sample.

Hematuria is the presence of blood in the urine and is a common condition in urological practice. It accounts for around 20% of urological referrals and is important, as it can be a cardinal symptom of urological malignancy. Around 40% of patients investigated for hematuria are found to have significant underling pathology, half of whom will have a urological malignancy. Therefore, all patients presenting with a single episode of haematuria require urgent investigation. Haematuria in adults should be regarded as a symptom of urological malignancy until proven otherwise.

Classification

Classification by the extent of hematuria

1. Dipstick hematuria: Detection of hemoglobin within red blood cells using reagent strips in macroscopically normal urine.This describes the use of reagent strips to detect blood chemically within urine.
2. Microscopic hematuria: Defined as the presence of more than two to five red blood cells per high powered field within macroscopically normal urine on a properly collected urinary specimen in the absence of an obvious benign cause.
3. Macroscopic hematuria:

Classification by the visibility of hematuria

1. Visible hematuria: Visible hematuria can be visualized with the naked eye and is also known as frank, gross or macroscopic hematuria. Visible hematuria is more likely to be associated with malignancy.
   1. Initial hematuria: May indicate urethral pathology
   2. Terminal hematuria: Hematuria at the end of the stream that comes from the proximal urethra (bladder neck/prostate).
   3. Complete hematuria: Hematuria throughout the entire stream suggests bladder, ureteric or renal pathology.
2. Non-visible hematuria: Non-visible hematuria encompasses dipstick and microscopic hematuria.

Classification by the duration of hematuria

1. Transient hematuria: A single urinalysis with hematuria is common and can result from menstruation, viral illness, allergy, exercise, or mild trauma.
2. Persistent or Significant hematuria: >3 RBCs/HPF on three urinalyses, a single urinalysis with >100 RBCs, or gross hematuria.

Age:

Young patients are more likely to have intrinsic renal pathology (i.e. glomerulonephritis whereas malignancy is more common in the elderly).

Sex:

Malignancy of the bladder and kidney is at least twice as common in males than in females. Women are more commonly affected by urinary tract infections.