What is a urinary tract infection?

Reading time: 1 min

Urinary tract infection is generally suspected if both the following are found: symptoms related to urination (e.g. pain, increased frequency but decreased urine volume or pain above the pubis) and finding urinary tract germs in a urine sample from the patient. 

Depending on the area of the urinary system infected, different symptoms and signs may occur and the diseases are named differently:  

- If the urethra is infected: Urethritis 

- If the bladder is infected: Cystitis 

- If the prostate is infected: Prostatitis 

- If the kidney is infected: Pyelonephritis 

- If a testicle is infected: Epididymitis or Orchiepididymitis 

Cystitis and urethritis are the only urinary tract infections that do not cause fever.  

The infection will have different features and evolution depending on the microorganism that causes it and the different individual factors for each patient. The more aggressive the germ, the easier it is to colonise the urinary system and the more serious the infection will be. 

If there are susceptible factors for the patient, the infection will be more common and serious. For example, immunosuppressed people, obstruction within the urinary system, significant residual urine after urination or the presence of probes, catheters or stones. 

The vast majority of germs that cause urinary tract infection are from the digestive system. Thus, it is important to control digestion disorders to prevent or treat a urinary tract infection (e.g. by controlling constipation or changes in the intestinal microbiota). 

Substantiated information by:

Agustín Franco
Ascensión Gómez Porcel
Pilar Luque
Verónica Rico Caballero

Published: 30 March 2022
Updated: 30 March 2022

The donations that can be done through this webpage are exclusively for the benefit of Hospital Clínic of Barcelona through Fundació Clínic per a la Recerca Biomèdica and not for BBVA Foundation, entity that collaborates with the project of PortalClínic.


Receive the latest updates related to this content.

Thank you for subscribing!

If this is the first time you subscribe you will receive a confirmation email, check your inbox

An error occurred and we were unable to send your data, please try again later.