What are the causes of urinary tract infection (UTI)

Urinary tract infection (UTI) is an infection that affects any part of the urinary system, from the kidneys, the bladder to the urethra. It is defined as the presence of microorganisms in some part of that system. When it affects the kidneys, it is called pyelonephritis, when the bladder, it is called cystitis in the urethra it is urethritis, and when it affects the prostate, it is called prostatitis.

The UTI can affect individuals of any age and sex, but it is far more common among women. This relationship is inverted in the first year of life when it is more common in boys. But why is UTI more frequent in women? This is probably due to anatomical factors. In women, the output of the urethra is very close to the entrance of the vagina, where it is known that the woman harbors many microorganisms in the vaginal flora.

In addition, poor hygiene after using the toilet, passing toilet paper into the anus and vagina favors the transport of intestinal microorganisms to the vulva. Another important factor is that the female urethra is much shorter than the male, which favors the path of bacteria from entering the urethra into the bladder.

UTI occurs primarily when microorganisms, bacteria in most cases, "climb" to reach the urethra and bladder, ureters and kidneys. The bacteria that most commonly cause UTI is called Escherichia coli, and is part of the normal intestinal flora. Thus, we can realize the importance of proper hygiene to prevent urinary infections.

Normally, urine does not contain any microorganism. The presence of any microorganism in the urine may lead to the development of UTI. Some people, especially women, may have bacteria in the urine and develop a UTI itself, being completely asymptomatic. These cases are called "asymptomatic bacteriuria" and are of particular importance in pregnant women, as we will comment further.

An extremely important factor in the development of UTI is urinary stasis. This happens when there is a difficulty emptying the bladder, and if urine accumulates for a long time. This favors the proliferation of bacteria in the urine, leading to the development of infection.

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