Urinary tract infections (UTIs)

A urinary tract infection (UTI) is a common infection which can involve any portion of the urinary system. The urinary system includes the kidneys (produce urine), ureters (tubes that carry the urine from the kidneys to the bladder), bladder (stores urine), and the urethra (the tube that carries urine from the bladder to outside the body).

Who's at risk for UTIs?

UTIs can affect men and women of all ages. Most urinary tract infections are caused by bacteria, and the anal region is a common source for these organisms. Infections generally develop in the lower urinary tract (bladder and urethra), but can progress to involve the upper urinary tract (ureters and kidneys).

Factors that affect UTI risk

  • Women are more prone to develop UTIs due to their shorter urethra
  • Sexual intercourse causes some women to develop UTIs for unknown reasons
  • Women who use a diaphragm or spermicidal foam are at increased risk for developing UTIs
  • Urinary catheterization (placement of a small tube in the urinary collecting system) can introduce bacteria into the urinary system
  • Obstruction of the bladder outlet (prostate enlargement in men, bladder stones)
  • Injuries to the bladder that prevent it from functioning normally (spinal cord injuries)
  • Pregnancy
  • Incomplete emptying of the bladder

Infections of the bladder are also called cystitis, and are the most common type of UTI.

Common UTI symptoms

  • A need to urinate urgently and frequently with small amount of urine voided
  • A sensation of pain or burning with urination
  • Blood in the urine
  • Cloudy or foul smelling urine
  • Cramps or tenderness over the bladder

Kidney infections, also referred to as pyelonephritis, tend to be more severe. Patients may have symptoms similar to cystitis paired with more severe symptoms.

Additional symptoms indicating a kidney infection

  • Fever and chills
  • Tenderness over the kidneys (located on either side of the spinal column, above the waist)
  • Nausea and vomiting

Diagnosing a UTI

The diagnosis of a UTI is made by examination of the urine with a chemical analysis (dipstick) or under the microscope (microscopy). A urine cultured may be ordered to determine the type of bacteria causing the infection. Urine cultures can take 24 to 72 hours to return. Depending on the scenario, your physician may order additional tests.

Treating a UTI

UTIs are commonly treated with oral antibiotics; how long you need to take them depends on the severity of the infection. In general, bladder infections in healthy people are treated for three to five days, in people with multiple medical problems a seven to 10 day course may be prescribed. 

Kidney infections are treated for seven to 14 days, and may require intravenous antibiotics. If there are other factors increasing the risk for recurrent infections, these are often managed after the main infection is cleared.

Preventive measures for recurrent infections include cranberry juice or cranberry extract tablets, vitamin C, probiotics, drinking plenty of fluid (60 to 80 ounces daily) and voiding regularly (every four hours).

Last reviewed: 
June 2017

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