A UTI is an infection of the urinary system that often causes discomfort and painful urination.
UTIs often start in the lower urinary tract. Urethritis, a very common lower urinary tract infection, starts in the urethra. Lower tract infections can also originate or spread to your bladder, a kind of UTI known as cystitis.
Some UTIs can begin in the upper urinary tract, in organs like the uterus, ureters, or kidneys. While this is rare, kidney infections (also known as Pyelonephritis), could be life-threatening if left untreated.
When most people get a UTI, they experience what doctors call an uncomplicated infection. An uncomplicated urinary tract infection is temporary and not usually the result of any underlying conditions affecting the urinary system. However, people who suffer from recurrent UTIs--infections that happen over and over again--may be suffering from a blockage in the urinary tract. Specialists in urology call these chronic infections complicated UTIs. Sometimes, urologists will use a test called cystoscopy, which examines the inside of the bladder, to diagnose the cause of recurrent UTIs.