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Isolated Hematuria

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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 HematuriaTables).

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

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