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Health Information Center

Urinary Tract Infection

  • Cynthia M. Johnson, MA
Publication Type:


Urinary Tract Infection

(UTI; Lower UTI)


A urinary tract infection (UTI) is an infection of any part of the urinary system. It can affect the:

The Urinary Tract.

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UTIs are caused by bacteria. The bacteria cling to the opening of the urethra where they grow and spread. The bacteria can enter the urethra and infect the bladder. They can also enter the bladder through the ureters and infect the kidneys.

Risk Factors

UTIs are more common in women. Other things that may raise the risk of a UTI are:

  • Being sexually active
  • Having a new sexual partner
  • Using spermicide
  • A personal history of UTIs
  • A history of UTIs in a sister, mother, or daughter

Some health issues may also raise the risk of a UTI, such as:


Some people may not have any symptoms. Others may have:

  • An urgent need to pass urine (pee)
  • Passing only small amounts of urine
  • Belly or pelvic area pain
  • Burning when passing urine
  • Cloudy, bad-smelling urine
  • Waking more often at night to pass urine
  • Leaking urine
  • Fever and chills
  • Nausea
  • Lack of hunger
  • Bloody urine
  • Low back pain or pain along the side of the ribs


The doctor will ask about symptoms and past health. A physical exam will be done. Urine will be tested for signs of infection.

Other tests may be done to look for a cause in people who have had UTIs in the past.


The goal of treatment is to cure the infection. This can be done with antibiotics. Other medicines may also be given to ease symptoms such as pain and bladder spasms.


The risk of a UTI can be lowered by:

  • Passing urine after having sex
  • Drinking plenty of fluids during the day
  • Avoiding spermicides




  • Bladder infection (urinary tract infection—UTI) in adults. National Institute of Diabetes and Digestive and Kidney Diseases website. Available at: https://www.niddk.nih.gov/health-information/urologic-diseases/bladder-infection-uti-in-adults.
  • Cystitis and urinary tract infections (UTI) in men. EBSCO DynaMed website. Available at: https://www.dynamed.com/condition/cystitis-and-upper-urinary-tract-infections-uti-in-men.
  • Uncomplicated urinary tract infection (UTI) (pyelonephritis and cystitis). EBSCO DynaMed website. Available at: https://www.dynamed.com/condition/uncomplicated-urinary-tract-infection-uti-pyelonephritis-and-cystitis.
  • What is a urinary tract infection (UTI) in adults? Urology Care Foundation website. Available at: https://www.urologyhealth.org/urology-a-z/u/urinary-tract-infections-in-adults.


  • Elizabeth Margaret Prusak, MD
Last Updated:

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.