 |
Hematuria: A Merck Manual of Patient Symptoms podcast
Hematuria is RBCs in urine; the urine may be red (macroscopic hematuria), bloody (gross hematuria), or not discolored (microscopic hematuria). Hematuria commonly occurs with other urine abnormalities (eg, proteinuria); isolated hematuria is urinary RBCs without other symptoms or urinary abnormalities. In people < 50, hematuria may be transient, resulting from exercise or sexual intercourse. Likely causes of persistent hematuria differ by age (see Table 3: Approach to the Genitourinary Patient: Causes of Isolated Hematuria ).
|
Table 3
|
| | |
|
Causes of Isolated Hematuria
|
|
Age (yr)
|
Common
|
Uncommon
|
|
0–15
|
Calculi and hypercalciuria
Congenital anomalies with obstruction
Contamination of urine specimen with menstrual blood
Glomerulopathy, such as IgA nephropathy, hereditary nephritis (Alport's syndrome), thin basement membrane disease (benign familial hematuria), and acute poststreptococcal glomerulonephritis
Sexual intercourse
Sickle cell disease
UTIs
Viral infection
|
Factitious
Fever
Hemolytic-uremic syndrome
Hemophilia
Henoch-Schönlein purpura
Schistosoma haematobium infection
|
|
15–50
|
Calculi and hypercalciuria
Contamination of urine specimen with menstrual blood
Exercise
Papillary necrosis
Polycystic kidney disease
Sexual intercourse
Sickle cell disease
UTIs
Viral infection
|
Arteriovenous malformations or fistulas
Disseminated intravascular coagulation
Factitious
Fever
Goodpasture's syndrome
Loin pain–hematuria syndrome
Medullary sponge kidney
Renal infarction
Renal vein thrombosis
Schistosoma haematobium infection
|
|
> 50
|
Benign prostatic hyperplasia
Cancer (renal, ureteral, bladder, or prostate)
Overanticoagulation
Polycystic kidney disease
Prostatitis
|
Arteriovenous malformations or fistulas
Cyclic hematuria in women
Endometriosis of the urethra
Factitious
Loin pain–hematuria syndrome
Renal vein thrombosis
Thrombotic thrombocytopenic purpura
Toxins, such as cantharidin or djenkol bean
|
|
Evaluation
History and physical
examination:
Isolated hematuria may be obvious based on red or bloody urine or detected only by urinalysis and microscopy. History, especially age, and physical examination occasionally give clues to the cause. However, urine and blood tests are required, and imaging tests are often needed.
Testing:
Hematuria detected by urine dipstick should be confirmed by microscopic examination; absence of RBCs suggests myoglobinuria or hemoglobinuria. In patients < 50 (including children), a 2nd negative dipstick implies transient hematuria and is usually sufficient to exclude serious causes unless patients have risk factors for renal calculi or bladder cancer (see Genitourinary Cancer: Bladder Cancer). If the 2nd dipstick is positive, a urine specimen should be sent for culture; positive culture warrants treatment with antibiotics. If hematuria resolves after treatment and no other symptoms are present, no further evaluation is required for patients < 50, especially women. When hematuria is confirmed microscopically and is of unknown origin, assessment of RBC morphology can help identify possible causes. RBCs of glomerular origin (dysmorphic, with spicules, folding, and blebs; nonglomerular RBCs retain their normal shape) should prompt evaluation and follow-up for intrinsic renal disorders; RBCs of nonglomerular origin suggest renal calculi or abnormalities of the GU tract, which should be evaluated by ultrasonography or CT with contrast. All patients ≥ 50 yr require cystoscopy, as do patients who are < 50 and who have risk factors for bladder cancer. If evaluation does not suggest a cause, men require prostate examination and possibly prostate-specific antigen testing to check for prostate disorders.
Collection of urine into 3 consecutive tubes is thought by some experts to distinguish urethral (in 1st tube) from bladder (in 3rd tube) sources of RBCs, but it is not a standard evaluation.
Treatment
Treatment involves treating the cause.
Last full review/revision November 2005
Content last modified November 2005
| |
