Urinary Tract Infection

Overview

Definition

A urinary tract infection (UTI) is an infection in any part of the urinary system including:

  • Upper tract:
    • Kidneys
    • Ureter—tubes from kidneys to bladder
  • Lower tract:
    • Bladder
    • Urethra—tubes from bladder that lets urine pass out of the body

The infection can cause swelling in the tract. This makes it painful to pass urine. The infection may be named for the specific area of the urinary tract that it effects:

  • Uretheral infection—urethritis
  • Bladder infection—cystitis
  • Kidney infection—pyelonephritis
The Urinary Tract
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Causes

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 factors 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

SymptomsandDiagnosis

Symptoms

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

Diagnosis

Your doctor will ask about your symptoms and medical history. A physical exam will also be done. A sample of your urine will be studied for:

  • Blood and pus
  • Exact type of bacteria (not always needed)

Frequent infections may be caused by a blockage or structure issues. Tests can show images of the urinary tract. Options may include:

  • CT scan
  • Ultrasound

Treatments

Treatment

UTIs are treated with antibiotics. You will probably start to feel better after 1-2 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. Your doctor may recommend medicine to help manage pain.

Prevention

To help decrease the risk of a UTI:

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

If the UTI is due to a problem with the urinary tract it may need to be fixed. The repair may help prevent future infections.

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.

a (UTI; Lower UTI)

RESOURCES

National Kidney Foundation https://www.kidney.org 

Urology Care Foundation http://www.urologyhealth.org 

CANADIAN RESOURCES

Canadian Urological Association http://www.cua.org 

Women's Health Matters http://www.womenshealthmatters.ca 

References

American College of Obstetricians and Gynecologists. ACOG Practice Bulletin No. 91: Treatment of urinary tract infections in nonpregnant women. Obstet Gynecol. 2008;111(3):785-794. Reaffirmed 2016.

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. Accessed September 7, 2017.

Jepson RG, Craig JC. Cranberries for preventing urinary tract infections. Cochrane Database Syst Rev. 2008;(1):CD001321.

Pohl A. Modes of administration of antibiotics for symptomatic severe urinary tract infections. Cochrane Database of Syst Rev. 2007;(4):CD003237.

Uncomplicated urinary tract infection (UTI) (pyelonephritis and cystitis). DynaMed Plus website. Available at: https://www.dynamed.com/topics/dmp~AN~T116894/Uncomplicated-urinary-tract-infection-UTI-pyelonephritis-and-cystitis. Updated March 15, 2017. Accessed November 30, 2017.

Urinary tract infection (UTI) in men. EBSCO DynaMed Plus website. Available at:  https://www.dynamed.com/topics/dmp~AN~T904748/Urinary-tract-infection-UTI-in-men . Updated January 26, 2017. Accessed September 7, 2017.

What is a urinary tract infection (UTI) in adults? Urology Care Foundation website. Available at: http://www.urologyhealth.org/urology/index.cfm?article=47. Accessed September 1, 2015.