Sandbox:Hematuria overview
Overview
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.
Definition
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.
classification
Classification by the extent of hematuria
- 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.
- 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.[1]
- Macroscopic hematuria: Defined as the presence of blood in urine that is visible with naked eye.
Classification by the visibility of hematuria
- Visible hematuria: Also known as Frank hematuria/ Macroscopic hematuria/ Gross hematuria.[2] 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.
- Initial hematuria: May indicate urethral pathology
- Terminal hematuria: Hematuria at the end of the stream that comes from the proximal urethra (bladder neck/prostate).
- Complete hematuria: Hematuria throughout the entire stream suggests bladder, ureteric or renal pathology.
- Non-visible hematuria: Non-visible hematuria encompasses dipstick and microscopic hematuria.[3]
Classification by the duration of hematuria
- Transient hematuria: A single urinalysis with hematuria is common and can result from menstruation, viral illness, allergy, exercise, fever, or mild trauma.
- Persistent or Significant hematuria: >3 RBCs/HPF on three urinalyses, a single urinalysis with >100 RBCs, or gross hematuria.
Causes
Life Threatening Causes
Common Causes
Causes by Organ System
Causes in Alphabetical Order
Differentiating Hematuria from other Diseases
Gross hematuria(GH) must be distinguished from pigmenturia, which may be due to endogenous sources (e.g., bilirubin, myoglobin, porphyrins), foods ingested (e.g., beets and rhubarb), drugs (e.g., phenazopyridine), and simple dehydration. This distinction can be made easily by urinalysis with microscopy. Notably, myoglobinuria and other factors can cause false-positive chemical tests for hemoglobin, so urine microscopy is required to confirm the diagnosis of hematuria. GH also must be distinguished from vaginal bleeding in women, which usually can be achieved by obtaining a careful menstrual history, collecting the specimen when the patient is not having menstrual or gynecologic bleeding, or, if necessary, obtaining a catheterized specimen. GH may also be detected by the presence of blood spotting on the undergarments of incontinent patients. After ruling out vaginal bleeding and mimics of hematuria, a urologic source must be suspected.
Red discoloration of the urine can have various causes:
- Red blood cells
- Microscopic hematuria (small amounts of blood, can be seen only on urinalysis or light microscopy)
- Macroscopic hematuria (or "frank" or "gross") hematuria
- Hemoglobin (only the red pigment, not the red blood cells)
- Other pigments
- Porphyrins in porphyria
- Betanin, after eating beets
Differentiating Hemoglobinuria from Myoglobinuria
| Centrifuse Result | |||||||||||||||||||||||||||||||||||||||||||
| Sediment Red | Supernatant Red | ||||||||||||||||||||||||||||||||||||||||||
| Hematuria | Dipstick heme | ||||||||||||||||||||||||||||||||||||||||||
| Negative | Positive | ||||||||||||||||||||||||||||||||||||||||||
| ❑ Beeturia ❑ Phenazopyridine ❑ Porphyria ❑ Other | ❑ Myoglobin ❑ Hemoglobin | ||||||||||||||||||||||||||||||||||||||||||
| Plasma color | |||||||||||||||||||||||||||||||||||||||||||
| Clear | Red | ||||||||||||||||||||||||||||||||||||||||||
| Myoglobinuria | Hemoglobinuria | ||||||||||||||||||||||||||||||||||||||||||
Epidemiology
2.5% of the general population has asymptomatic 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.
Natural history, complications and prognosis
The prognosis depends on the severity of the disease. Finding the cause is the main factor which determines the prognosis. As hematuria has a vast majority of causes the complications depends on the specific etiology.
References
- ↑ Davis R, Jones JS, Barocas DA, Castle EP, Lang EK, Leveillee RJ et al. (2012) Diagnosis, evaluation and follow-up of asymptomatic microhematuria (AMH) in adults: AUA guideline. J Urol 188 (6 Suppl):2473-81. DOI:10.1016/j.juro.2012.09.078 PMID: 23098784
- ↑ Pan, Cynthia G. (2006). "Evaluation of Gross Hematuria". Pediatric Clinics of North America. 53 (3): 401–412. doi:10.1016/j.pcl.2006.03.002. ISSN 0031-3955.
- ↑ "www.surgeryjournal.co.uk".