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Pathophysiology:

The urinary tract, from the kidneys to the urethral meatus,

is normally sterile and resistant to bacterial colonization

despite frequent contamination of the distal urethra withcolonic bacteria. Mechanisms that maintain the tract's sterility

include urine acidity, emptying of the bladder at micturition,

ureterovesical and urethral sphincters, and various immunologic

and mucosal barriers.

About 95% of UTIs occur when bacteria ascend the urethra to the

bladder and, in the case of acute uncomplicated pyelonephritis,

ascend the ureter to the kidney. The remainder of UTIs are

hematogenous. Systemic infection can result from UTI,

particularly in the elderly. About 6.5% of cases of hospital-

acquired bacteremia are attributable to UTI.

A urinary tract infection is an infection of any of the organs

in the urinary tract, which consist of the bladder, the ureter,

the urethra, and the kidneys.

A urinary tract infection (UTI) may occur in the: Bladder -

Cystitis is an infection of the bladder. This is the most common

form of UTI; it can be aggravated if the bladder does not empty

completely when you urinate. Urethra - Urethritis is

infection/inflammation of the urethra. This can be due to other

things besides the organisms usually involved in UTI¶s; in

particular, many sexually transmitted diseases (STD¶s) appear

initially as urethritis. Ureter ± Ureteritis is infection of a

ureter. This can occur if the bacteria entered the urinary tract

from above, or if the ureter-to-bladder valves don¶t work

properly and allow urine to ³reflux´ from the bladder into the

ureters. Kidney ± Pyelonephritis is an infection of the kidney

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y Women with lowered immunity

y Women with obstructions in the urinary tract

Signs and Symptoms of UTI

y Burning sensation at the start of urination

y Burning sensation in the middle of urination

y F ever

y L ower abdominal pain

y F unny smell, color, or appearance (cloudy, dark, blood

tinged) of urine

y Pain in back, flanks, or abdomen

y N ausea

y V omiting

Other Signs and Symptoms of UTI

y Uncomfortable pressure above pubic bone

y F ullness in rectum (in men only)

y Small amount of urine, despite urge to urinate

y Irritability (in children only