Urinary tract infection

Definition

A urinary tract infection, or UTI, is an infection that can happen anywhere along the urinary tract. The urinary tract includes the:

• Bladder
• Kidneys
• Ureters -- the tubes that take urine from each kidney to the bladder
• Urethra -- the tube that empties urine from the bladder to the outside

Alternative Names

Causes

Cystitis, a common condition, is usually caused by bacteria entering the urethra and then the bladder. This leads to inflammation and infection in the lower urinary tract.

Certain people are more likely to get UTIs. Women tend to get them more often because their urethra is shorter and closer to the anus. Elderly people (especially those in nursing homes) and people with diabetes also get more UTIs.

Some children develop UTIs. In boys, they are most common before the first birthday. In young girls, UTIs are most common around age 3, overlapping with the toilet training period.

Cystitis in children can be promoted by abnormalities in the urinary tract. Therefore, children with cystitis, especially those under age 5, deserve special follow-up to prevent later kidney damage.

The following risk factors increase your chances of getting a UTI:

• Bowel incontinence
• Catheterization
• Kidney stones
• Immobility (for example, during recovery from a hip fracture)
• Menopause
• Narrowed urethra
• Not drinking enough fluids
• Pregnancy
• Prostate inflammation or enlargement
• Sexual intercourse, especially if you have multiple partners
• Using a diaphragm for birth control

References

Cincinnati Children's Hospital Medical Center. Evidence-based care guideline for medical management of first urinary tract infection in children 12 years of age or less. Cincinnati (OH): Cincinnati Children's Hospital Medical Center; 2006 Nov. 23 p.

Walsh, PC, ed. Campbell’s Urology. 8th ed. Philadelphia, Pa: Saunders; 2002.

Marx JA, Hockberger RS, Walls RM, eds. Rosen’s Emergency Medicine: Concepts and Clinical Practice. 5th ed. St. Louis, Mo: Mosby; 2002.