A urinary tract infection (UTI) is an infection of any part of the urinary system. The urinary system consists of the kidneys, bladder, ureters and urethra. The kidneys are filters that remove excess fluid, electrolytes and waste from the blood, while retaining the important elements. Each kidney has a ureter, a small tube that allows urine from the kidney to pass into the bladder. When the bladder is full, the urine leaves the body through a tube called the urethra. UTIs usually affect the bladder or the urethra first, and can then spread to the ureters and the kidneys if left untreated.
Types of UTIs
Cystitis (bladder infections)
A common type of UTI, cystitis is the inflammation of the bladder. It is usually caused by a bladder infection.
Pyelonephritis (kidney infections)
Another type of UTI is the painful kidney infection caused by cystitis. In some cases, the bacteria from the bladder can travel up towards one or both kidneys.
Urethritis (urethra infections)
Urethritis is the inflammation of the urethra usually caused by an infection.
