An urinary system disease that is characterized by an infection in any part of the urinary system, including the kidneys, ureters, bladder or urethra. [ url:https://www.mayoclinic.org/diseases-conditions/urinary-tract-infection/symptoms-causes/syc-20353447 url:https://medlineplus.gov/urinarytractinfections.html url:https://www.cdc.gov/antibiotic-use/community/for-patients/common-illnesses/uti.html ]