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Asymptomatic Bacteriuria


Talha H. Imam

, MD, University of Riverside School of Medicine

Last full review/revision Jul 2021| Content last modified Jul 2021
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Asymptomatic bacteriuria is a condition in which larger than normal numbers of bacteria are present in the urine but symptoms do not result.

Asymptomatic bacteriuria is common in certain groups of people, such as those who have bladder catheters inserted for an extended period. Asymptomatic bacteriuria is not normally treated because eradicating the bacteria can be difficult and complications are usually rare. Also, giving antibiotics can alter the balance of bacteria in the body, sometimes allowing bacteria to flourish that are more difficult to eliminate.

Did You Know...

  • Most people who have excess bacteria in the urine and have no symptoms should not be treated.

An exception is if the person has a condition that makes a urinary tract infection (UTI) particularly risky. Such conditions may include

For example, a bladder infection (cystitis Bladder Infection Cystitis is infection of the bladder. Usually, bacteria are the cause of cystitis. A frequent need to urinate and pain or burning while urinating are the most common symptoms. Doctors can often... read more Bladder Infection ) can seriously complicate pregnancy by ascending to the kidneys and causing a kidney infection (pyelonephritis Kidney Infection Pyelonephritis is a bacterial infection of one or both kidneys. Infection can spread up the urinary tract to the kidneys, or uncommonly the kidneys may become infected through bacteria in the... read more ), leading to early labor. Also, a UTI can damage a transplanted kidney. A UTI can cause potentially fatal bloodstream infection Sepsis and Septic Shock Sepsis is a serious bodywide response to bacteremia or another infection plus malfunction or failure of an essential system in the body. Septic shock is life-threatening low blood pressure ... read more in people whose immune system is suppressed by a drug or disorder. Sometimes, the immune system becomes suppressed after cancer chemotherapy. Asymptomatic bacteriuria is also sometimes treated in people who have certain kinds of kidney stones Stones in the Urinary Tract Stones (calculi) are hard masses that form in the urinary tract and may cause pain, bleeding, or an infection or block of the flow of urine. Tiny stones may cause no symptoms, but larger stones... read more Stones in the Urinary Tract that cannot be eliminated (and thus cause repeated UTIs) and in people scheduled to have a urinary tract surgical procedure done.

Because asymptomatic bacteriuria is not usually treated, doctors do not usually do tests to identify it unless the person has a condition that warrants such treatment. Bacteriuria can be confirmed by a urine culture Urinalysis and Urine Culture Urinalysis, the testing of urine, may be necessary in the evaluation of kidney and urinary tract disorders and can also help evaluate bodywide disorders such as diabetes or liver problems. A... read more Urinalysis and Urine Culture , in which bacteria from a urine sample are grown in a laboratory to identify the numbers and type of bacteria. Newer molecular urine testing may sometimes reveal unusual pathogens for recurrent UTI and those that are resistant to treatment. When treatment is warranted, antibiotic therapy is given.

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Tubulointerstitial Nephritis
The kidneys contain tubules, which are structures in the kidneys that are involved in filtering fluids. Tubulointerstitial nephritis is inflammation that affects the tubules and the tissue surrounding them, called “interstitial tissue.” Onset of tubulointerstitial nephritis may be acute (sudden) or chronic (gradual) and often results in kidney failure. Which of the following is the most common cause of acute tubulointerstitial nephritis?
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