The urinary tract makes and stores urine, one of the body's liquid waste products. The urinary tract includes the following parts:

  • Kidneys, which produce urine by removing waste and water from the blood
  • Ureters, the tubes that carry urine from the kidneys to the bladder
  • Bladder, the sac-like container for storing urine
  • Urethra, the tube that carries urine from the bladder to outside of the body

What is a urinary tract infection?

Normal urine contains no bacteria (germs). Sometimes, however, bacteria from outside the body get into the urinary tract, and cause infection and inflammation. This is a urinary tract infection. The infection can involve the urethra (a condition called urethritis), kidneys (a condition called pyelonephritis) or bladder, (a condition called cystitis). Cystitis is the most common type of urinary tract infection.

What are the symptoms of a urinary tract infection?

A urinary tract infection causes the lining of the urinary tract to become red and irritated, which may produce some of the following symptoms:

Other symptoms that may be associated with a urinary tract infection include:

What causes a urinary tract infection?

Urinary tract infections are caused by microorganisms—usually bacteria—that enter the urethra and bladder, causing inflammation and infection. The bacteria also may travel up the ureters and infect the kidneys.

More than 90 percent of cystitis cases are caused by E. coli, a bacterium normally found in the intestines.

How common are urinary tract infections?

Urinary tract infections are very common, occurring in 1 out of 5 women sometime in their lifetime. One to 2% of children develop urinary tract infections. Each year, 8 million to 10 million visits to doctors are for urinary tract infections.

Who gets urinary tract infections?

Anyone can get a urinary tract infection, but they are more common in women. This is because the urethra in females is shorter and closer to the anus, where E. coli bacteria are common. Older adults also are at higher risk for developing cystitis. This increased risk may be due to incomplete emptying of the bladder related to various medical conditions, including an enlarged prostate or a bladder prolapse (i.e., falling down or slipping of the bladder from its usual position). If you get frequent urinary tract infections, your doctor may do tests to check for other health problems—such as diabetes or an abnormal urinary system—that may be contributing to your infections.

How are urinary tract infections diagnosed?

Your doctor will use the following tests to diagnose a urinary tract infection:

  • Urinalysis to examine the urine for red blood cells, white blood cells and bacteria (The number of white and red blood cells can indicate an infection.)
  • Urine culture to determine the type of bacteria in the urine. This is important to help determine the appropriate treatment.

If your infection does not respond to treatment or if you get repeated infections, your doctor may use the following tests to examine your urinary tract for disease or injury:

  • Intravenous pyelogram (IVP), a series of X-rays of the bladder, kidneys and ureters after a special dye is injected (The dye helps the structures to show up better on the X-ray.)
  • Ultrasound, a test that uses sound waves to form images of internal organs
  • Cystoscopy, a test that uses a special instrument fitted with a lens and a light source (cystoscope) to see inside the bladder from the urethra
  • CT scan, a type of X-ray that takes cross sections of the body (like slices) – much more precise than typical X-rays

How are urinary tract infections treated?

Antibiotics, medicines that kill the bacteria, are used to treat urinary tract infections. Your doctor will choose a drug that best treats the bacteria causing your infection. Commonly used antibiotics include:

  • Nitrofurantoin
  • Sulfonamides (sulfa drugs)
  • Amoxicillin
  • Cephalosporins
  • Trimethoprim/sulfamethoxazole (Bactrim®)
  • Doxycycline
  • Quinolones (such as ciprofloxacin [Cipro®])

It is very important that you follow your doctor's directions for taking the medicine. Do not stop taking the antibiotic because your symptoms go away and you start feeling better. If you have a history of frequent urinary tract infections, you may be given a prescription for antibiotics that you would take at the first onset of symptoms. Other patients may be given antibiotics to take every day, every other day, or after sexual intercourse to prevent the infection. If the infection is not treated completely with the full course of antibiotics, it can return.

What are the complications of a urinary tract infection?

A urinary tract infection that is not treated can lead to a more serious infection of the kidneys.

Can urinary tract infections be prevented?

There are some steps you can take to reduce your risk of developing a urinary tract infection:

  • Follow good hygiene practices of the genital area (especially women). After a bowel movement, the genitals should be wiped from front to back to reduce the chance of dragging E. coli bacteria from the rectal area to the urethra.
  • Urinate frequently. This flushes bacteria out of the bladder and may reduce the risk of cystitis in those who are prone to urinary tract infections. Drinking plenty of fluids encourages frequent urination. Avoid fluids and foods that irritate the bladder, such as alcohol, citrus juices, drinks containing caffeine and spicy foods. Also avoid smoking during this time.
  • Urinate immediately before and after sex. This may help flush out bacteria that may have been introduced during intercourse. Wash the genital area with warm water before having sex.
  • Apply an estrogen-containing vaginal cream in post-menopausal women to reduce the risk of a urinary tract infection. Your physician will decide with you if this is something that may benefit you. The estrogen cream changes the pH of the vagina to make one less susceptible to infections.
  • Drink at least 6-8 glasses of water a day
  • Don't douche
  • Don't use feminine deodorants on your genital area
  • Change tampons and feminine pads often
  • Use a water-based lubricant during sex if you have vaginal dryness
  • Check with your doctor if you think your diaphragm is causing infection
  • Wear cotton underwear
  • Take showers instead of baths
  • Avoid tight-fitting clothing and pantyhose

What is the prognosis (outlook) for a person with a urinary tract infection?

While urinary tract infections may be uncomfortable, they generally respond well to treatment.

When should I call my health care provider?

Call your health care provider if you have symptoms of a urinary tract infection. Also call if you have been diagnosed with an infection and your symptoms get worse or you develop new symptoms, especially fever, back pain and vomiting.


