In the general population, the prevalence of asymptomatic gross hematuria is about 2.5% while the prevalence of asymptomatic microhematuria is about 13%.

Mohr DN, Offord KP, Owen RA, et al.: Asymptomatic microhematuria and urologic disease.

Hiatt RA, Ordoñez JD: Dipstick urinalysis screening, asymptomatic microhematuria, and subsequent urological cancers in a population-based sample.

A longer follow-up of the HMO study indicated that individuals with microhematuria were at a higher risk for subsequent development of muscle-invading bladder cancer, with a latency of 3.5 to 14.5 years.

Messing EM, Young TB, Hunt VB, et al.: The significance of asymptomatic microhematuria in men 50 or more years old: findings of a home screening study using urinary dipsticks.

Microscopic hematuria is a medical condition in which urine contains small amounts of blood.

It is a benign condition that causes persistent microscopic hematuria.

Microscopic hematuria still showing up in urine.

Most patients with thin basement membrane disease are incidentally discovered to have microscopic hematuria on urinalysis.

A smaller proportion (20-30%), usually the older population, have microscopic hematuria and proteinuria (less than 2 gram/day).

Microscopic hematuria (small amounts of blood, can be seen only on urinalysis or light microscopy)

The gross hematuria resolves after a few days, though microscopic hematuria may persist.

However, a biopsy is rarely done in cases where the patient has isolated microscopic hematuria, normal kidney function, and no proteinuria.

Routine urinalyses among middle-aged adults conducted by medical clinics around the country have revealed that 13 to 15 percent have microscopic hematuria.

Patients with Epstein Syndrome have persistent proteinuria, microscopic hematuria, moderate hypertension, and a bilateral high frequency sensor neural hearing loss.

This blood in the urine may be visible to the naked eye (gross/macroscopic hematuria) or detectable only by microscope (microscopic hematuria).

For example, 5 percent of young men in the Israeli Air Force and 4 percent of Finnish schoolchildren were shown to have microscopic hematuria.

Moschcowitz noted that his patient, a 16 year-old girl, had anemia, petechiae (purpura), microscopic hematuria, and, at autopsy, disseminated microvascular thrombi.

In blunt injury, imaging is indicated if there is gross hematuria, or if the patient exhibits shock together with either gross or microscopic hematuria.

However, patients with isolated microscopic hematuria (i.e. without associated proteinuria and with normal kidney function) are not usually biopsied since this is associated with an excellent prognosis.

Focal glomerulonephritis is usually associated with only mild microscopic hematuria and proteinuria; a transition to a more diffuse form of renal involvement is associated with more severe disease.

If, in contrast, all such patients are biopsied, then the group with isolated microscopic hematuria and isolated mesangial IgA will be included and 'improve' the prognosis of that particular series.

Chronic renal failure (no previous symptoms, presents with anemia, hypertension and other symptoms of renal failure, in people who probably had longstanding undetected microscopic hematuria and/or proteinuria)

The blood in the urine may be present in microscopic amounts (microscopic hematuria) and not visible to the eye, present in small amounts that give the urine a "cloudy" or "smoky" appearance, or easily visible.

The American Urological Association (AUA) recommends a definition of microscopic hematuria as three or more red blood cells per high-power microscopic field in urinary sediment from two of three properly collected urinalysis specimens.

Microscopic haematuria with or without proteinuria may be seen.

Microscopic haematuria and hypertension may also been seen.

Many physicians also believe that simple renal cysts commonly cause microscopic haematuria and mild proteinuria.

Inhalation or skin contact with 4-COT produces acute toxic effects, initially appearing as macroscopic or microscopic haematuria.

For example, should further diagnostic procedures (such as renal biopsy) be performed, after simple renal cysts are found in a patient with mild proteinuria or microscopic haematuria?

Sultana SR, Goodman CM, Byrne DJ, et al.: Microscopic haematuria: urological investigation using a standard protocol.

In the only documented case in which rechallenge has been undertaken, low dose rechallenge with both mesalazine and sulphasalazine caused microscopic haematuria suggesting dose independent hypersensitivity to 5-ASA.

Interestingly, neither the prevalence of past symptoms nor that of proteinuria and microscopic haematuria differed in patients with and without simple renal cysts, and the red blood cell count was also the same in both groups.