Urinary Tract Infection



UTIs are caused by bacteria. The bacteria cling to the opening of the urethra. There they begin to grow and spread. The infection can then move up into the bladder. If the infection is not treated it can spread to the kidney. It can then lead to a severe kidney infection.

The bacteria often come from the colon or vagina. They are passed or moved toward the urethra.

Risk Factors

UTIs are more common in women. Other things that may increase your chance of a UTI include:

  • Being sexually active
  • Use of spermicide
  • New sexual partner
  • History of UTIs in sister, mother, or daughter

Some conditions may increase the chance of a UTI:

  • Diabetes
  • Weak immune system
  • Pregnancy
  • Menopause
  • Bladder catheter in place or recently used
  • Neurogenic bladder
  • Renal insufficiency
  • Kidney stones
  • Problems in the urinary tract that slow the flow of urine, such as vesicoureteral reflux or polycystic kidneys
  • History of kidney transplant
  • Tumor



Some may not have any symptoms. Those that do have symptoms may have:

  • Urgent need to urinate
  • Small amounts of urine during urination
  • Pain in the abdomen or pelvic area
  • Burning sensation during urination
  • Cloudy, bad-smelling urine
  • Increased need to get up at night to urinate
  • Leaking of urine
  • Fever and chills
  • Nausea and low desire to eat

An infection in the kidney can be more serious. Call your doctor right away if you have symptoms of a kidney infection, such as:

  • Bloody urine
  • Low back pain or pain along the side of the ribs
  • High fever and chills


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

Frequent infections may be caused by a blockage or structure issues. Images of the urinary tract may be taken with:

  • CT scan
  • Ultrasound



UTIs are treated with antibiotics. They can start to ease symptoms within 1 to 2 days. It is important to take all of the medicine, even if you feel better. A hospital stay may be needed with a severe infection. The antibiotics can then be delivered through an IV.

The infection may cause pain and spasms in the bladder. Medicine can help to ease spasms.


To help decrease the risk of a UTI:

  • Empty your bladder completely after sex. Drink a full glass of water.
  • Drink plenty of fluids throughout the day.

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.

Edits to original content made by Denver Health.