Urinary Tract Infection (UTI) is the infection of the urinary tract, usually caused by microbes. The urinary tract comprises of the kidneys, ureters, bladder and the urethra. Bacteria have been found to be the cause for most of the UTIs, while fungi cause some of them. Viral infections occur rarely and are usually seen in patients who might have undergone organ transplants or suffering from other medical conditions that will weaken the immune system.
Most of the Urinary Tract Infection (UTI) are known to affect only the urethra and the bladder in the lower tract. But, they can affect the ureters and kidneys too, in the upper tract but they are rare and usually severe.