Urinary system consists of parts such as kidney, ureters, bladder and urethra. Urinary tract infection is the infection of urinary tract. Usually the parts of the system that are infected in urinary tract infection are bladder and urethra but it can involve bladder and kidney. If infection is limited to urethra than it is called as urethritis, if kidneys are involved it is called as pyelonephritis and if bladder is involved it is described as cystitis. Women are more prone to infections than men due to their anatomically smaller length of urethra.