What Is Urinary Tract Infection?

A urinary tract infection (UTI) is an infection in any part of your urinary system — your kidneys, ureters, bladder and urethra. Most infections involve the lower urinary tract — the bladder and the urethra.

The urine is normally sterile. An infection occurs when bacteria get into the urine and begin to grow. The infection usually starts at the opening of the urethra where the urine leaves the body and moves upward into the urinary tract.

Most urinary tract infections are bladder infections. A bladder infection usually is not serious if it is treated right away. If you do not take care of a bladder infection, it can spread to your kidneys. A kidney infection is serious and can cause serious damage.

What Causes Urinary Tract Infections?

Urinary tract infections typically occur when bacteria enter the urinary tract through the urethra and begin to multiply in the bladder. Although the urinary system is designed to keep out such microscopic invaders, these defenses sometimes fail. When that happens, bacteria may take hold and grow into a full-blown infection in the urinary tract.

You may be more likely to get an infection if you do not drink enough fluids, you have diabetes, or you are pregnant. The chance that you will get a bladder infection is higher if you have any problem that blocks the flow of urine from your bladder. Examples include having kidney stones or an enlarged prostate gland. The most common UTIs occur mainly in women and affect the bladder and urethra.

What Are the Symptoms of UTI?

You may have an infection if you have any of these symptoms:

  • You feel pain or burning when you urinate.
  • You feel like you have to urinate often, but not much urine comes out when you do.
  • Your belly feels tender or heavy.
  • Your urine is cloudy or smells bad.
  • You have pain on one side of your back under your ribs. This is where your kidneys are.
  • You have fever and chills.
  • You have nausea and vomiting.
  • Pelvic pain, in women — especially in the center of the pelvis and around the area of the pubic bone.

How Are Urinary Tract Infections Diagnosed and Treated?

Tests and procedures used to diagnose urinary tract infections include:

  • Analyzing a urine sample.
  • Growing urinary tract bacteria in a lab. Lab analysis of the urine is sometimes followed by a urine culture. This test tells your doctor what bacteria are causing your infection and which medications will be most effective.
  • Creating images of your urinary tract (having an ultrasound, a computerized tomography (CT) scan or magnetic resonance imaging (MRI). Your doctor may also use a contrast dye to highlight structures in your urinary tract.
  • Using a scope to see inside your bladder.

Antibiotics usually are the first line of treatment for urinary tract infections. Which drugs are prescribed and for how long depend on your health condition and the type of bacteria found in your urine.

Your doctor may also prescribe a pain medication (analgesic) that numbs your bladder and urethra to relieve burning while urinating, but pain usually is relieved soon after starting an antibiotic.

For a severe UTI, you may need treatment with intravenous antibiotics in a hospital.

When treated promptly and properly, lower urinary tract infections rarely lead to complications. But left untreated, a urinary tract infection can have serious consequences, including: recurrent infections, permanent kidney damage, increased risk in pregnant women of delivering low birth weight or premature infants, urethral narrowing (stricture) in men from recurrent urethritis, and sepsis, a potentially life-threatening complication of an infection, especially if the infection works its way up your urinary tract to your kidneys.

Prevention

You can take these steps to reduce your risk of urinary tract infections:

  • Drink plenty of liquids, especially water.
  • Drink cranberry juice.
  • Wipe from front to back. Doing so after urinating and after a bowel movement helps prevent bacteria in the anal region from spreading to the vagina and urethra.
  • Avoid potentially irritating feminine products. Using deodorant sprays or other feminine products, such as douches and powders, in the genital area can irritate the urethra.
  • If you are a woman, urinate right after having sex.
  • Change your birth control method. Diaphragms, or unlubricated or spermicide-treated condoms, can all contribute to bacterial growth.
  • Urinate often. Do not try to hold it.