How to Treat UTI Naturally? Introduction A urinary tract infection (UTI) is an infection of the urinary system which can affect any part of the urinary system may be kidneys, ureters, bladder, and urethra. When the infection affects the lower urinary tract (the bladder and the urethra) it is known as cystitis (bladder infection) and when it affects the upper urinary tract (kidneys) it is known as pyelonephritis (kidney infection). Symptoms of Urinary Tract Infection (UTI) The symptoms of  UTI