Hematuria: Practice Essentials, Background, Pathophysiology

broadly, hematuria is defined as the presence of 5 or more loss blood cells ( RBCs ) per high-octane airfield in 3 of 3 consecutive centrifuged specimens obtained at least 1 workweek apart. ( See the image below. ) hematuria can be either crying ( i, overtly bloody, smoky, or tea-colored urine ) or microscopic. It may besides be either diagnostic or asymptomatic, either ephemeral or persistent, and either isolated or associated with proteinuria and other urinary abnormalities. [ 1 ]
Asymptomatic ( isolated ) hematuria broadly does not require discussion. In conditions associated with abnormal clinical, testing ground, or imaging studies, treatment may be necessary, as appropriate, with the chief diagnosis .

Microscopy of urinary sediment. Typical appearance
Microscopy of urinary sediment. typical appearance in non-glomerular hematuria : red blood cell are uniform in size and shape but show two populations of cells because a small number have lost their hemoglobin pigment.

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Signs and symptoms

The first base footprint in the evaluation of hematuria consists of a detail history and a exhaustive physical examination. Efforts should be made to distinguish glomerular causes from extraglomerular ones, as follows :

  • passage of clots in urine suggests an extraglomerular induce .
  • Fever, abdominal pain, dysuria, frequency, and holocene enuresis in older children may point to a urinary tract infection as the causal agent .
  • holocene trauma to the abdomen may be indicative mood of hydronephrosis .
  • Early-morning periorbital swelling, weight gain, oliguria, dark-colored urine, and edema or high blood pressure suggest a glomerular cause .
  • Hematuria due to glomerular causes is painless .
  • recent throat or skin infection may suggest postinfectious glomerulonephritis .
  • articulation pains, hide rashes, and prolonged fever in adolescents suggest a collagen vascular perturb .
  • Anemia can not be accounted for by hematuria alone ; in a affected role with hematuria and lividness, other conditions should be considered .
  • Skin rashes and arthritis can occur in Henoch-Schönlein purpura and systemic lupus erythematosus .
  • information regarding use, menstruation, late bladder catheterization, intake of certain drugs or toxic substances, or passage of a calculus may besides assist in the derived function diagnosis .
  • A family history that is suggestive of Alport syndrome, collagen vascular diseases, urolithiasis, or polycystic kidney disease is authoritative .

physical examination should include the play along :

  • measurement of the blood pressure ( with an appropriately sized cuff )
  • evaluation for the presence of periorbital ostentation or peripheral edema
  • Detailed clamber examination to look for purpura and/or petechia
  • abdominal examination to look for palpable kidneys
  • careful examination of the genitalia
  • Detailed ophthalmologic evaluation ( in familial hematuria )

The follow findings help distinguish between glomerular and nonglomerular hematuria :

  • glomerular hematuria : Brown-colored urine, RBC casts, and dysmorphic ( small, deformed, misshapen, sometimes fragmented ) RBCs and albuminuria
  • Nonglomerular hematuria : red or pink urine, passage of blood clots, and eumorphic ( normal-sized, biconcavely shaped ) erythrocytes

See clinical Presentation for more detail .


The lab tests ordered for the evaluation of hematuria must be based on the clinical history and the forcible examination. Tests that may be helpful include the surveil :

  • urinalysis with careful microscopic review of the urine sample .
  • Phase-contrast microscopy to help determine the generator of the shed blood. In clinical practice this test is not always feasible .
  • Electrolyte, lineage urea nitrogen ( BUN ), and serum creatinine levels .
  • Hematologic and curdling studies ( eg, arrant blood count [ CBC ] and, sometimes, platelet counts ) .
  • Random urine calcium and creatinine levels .
  • serologic examination ( eg, complement, antistreptolysin [ ASO ], anti-DNase B, antinuclear antibody [ ANA ], and double-stranded DNA [ dsDNA ], ANCA ) .
  • urine culture for suspected urinary tract infection ( UTI ) .

The following imagination studies may be helpful :

intravenous urography rarely contributes extra information in the evaluation of hematuria and results in unnecessary vulnerability to ionizing radiation .

A kidney biopsy is rarely indicated in the evaluation of isolated asymptomatic hematuria. proportional indications for performing a kidney biopsy in patients with hematuria are as follows :

  • significant albuminuria
  • Abnormal nephritic function
  • perennial persistent hematuria
  • serologic abnormalities ( abnormal complement, ANA, or dsDNA levels )
  • Recurrent arrant hematuria
  • A family history of end-stage nephritic disease

In most patients, a nephritic biopsy either is normal or reveals minor changes, such as sparse glomerular basement membranes, focal glomerulonephritis, or mild mesangial hypercellularity. In a minority of patients, histological findings, together with historic or serologic data, may point to specific conditions .

Hematuria may be categorized as follows :

  • Gross hematuria
  • Microscopic hematuria with clinical symptoms
  • asymptomatic microscopic hematuria with proteinuria
  • asymptomatic microscopic ( isolated ) hematuria

See Workup for more contingent .


General principles of treatment are as follows :

  • Hematuria is a signboard and not itself a disease ; therefore, therapy should be directed at the cause .
  • Asymptomatic ( isolated ) hematuria broadly does not require treatment .
  • In conditions associated with abnormal clinical, lab, or imaging studies, treatment may be necessity, as allow, with the primary diagnosis .
  • surgical intervention may be necessary with certain anatomic abnormalities ( eg, ureteropelvic junction obstacle, tumor, or significant urolithiasis ) but not necessarily to treat hematuria .
  • Unlike in adults, cystoscopy does not contribute to the diagnosis in the majority of children .
  • dietary modification is normally not indicated .
  • Patients with dogged microscopic hematuria should be monitored every 6-12 months for the appearance of signs or symptoms indicative of progressive nephritic disease .

See Treatment and Medication for more contingent .

Guidelines on hematuria from the American College of Physicians ( ACP ) advise that clinicians should include gross hematuria in their everyday review of systems and specifically ask all patients with microscopic hematuria about any history of gross hematuria. [ 2 ]

The ACP besides makes the follow recommendations [ 2 ] :

  • Clinicians should confirm heme-positive results of dipstick testing with microscopic urinalysis that demonstrates 3 or more erythrocytes per high-powered field before initiating promote evaluation in all asymptomatic patients.

  • Clinicians should pursue evaluation of hematuria even if the patient is receiving antiplatelet or anticoagulant therapy .
  • Clinicians should not obtain urinary cytology or other urine-based molecular markers for bladder cancer detection in the initial evaluation of hematuria .

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