A urinary (YOOR-ih-nair-e) tract infection, or UTI, is an infection that occurs in any part of the urinary tract. The urinary
tract is made up of the urethra*, bladder*, ureters*, and kidneys.
What Are UTIs?
A UTI usually is caused by bacteria. The bacterium most often responsible for UTIs is Escherichia coli (eh-sher-IH-she-ah
KOH-lye). Many kinds of E. coli bacteria normally are found in human intestines* (and the vagina in women), but sometimes
they are able to make their way into the urethra. When this happens, the bacteria can spread up into other parts of the urinary
tract and cause an infection. Other types of bacteria from the intestines and some viruses also can produce infections in
the urinary tract. The bacteria Chlamydia (kla-MIH-dee-uh) and Mycoplasma (my-ko-PLAZ-muh) can cause UTIs as well, but these
types of infections usually stay in the urethra or reproductive system.
The type of UTI that a person contracts depends on which part of the urinary system is infected with bacteria. When bacteria
grow in the urethra and cause inflammation, it is called urethritis (yoo-ree-THRY-tis). If the infection involves the bladder,
it is called cystitis (sis-TIE-tis). If infection has spread to the kidneys, it is called pyelonephritis (py-uhlo-nih-FRY-tis).
How Common Are UTIs?
Urinary tract infections are very common: millions of people, especially women, have them every year. It is estimated
that 1 in 5 women will have at least one UTI in her lifetime, and some women have them repeatedly. UTIs are not uncommon in
children; by the time children reach their eleventh birthday, 3 in 100 girls and 1 in 100 boys will have had a UTI. Women
and girls are at a higher risk of UTIs because the urethra is much shorter in a woman than it is in a man. A shorter urethra
means a shorter distance for bacteria to travel to enter the urinary tract. Also, because the opening of the urethra is much
closer to the anus* in females, if a girl has a bowel movement and any bacteria are left on the skin nearby, it is easy for
them to invade the urethra.
*urethra (yoo-REE-thra) is the tube through which urine passes from the bladder to the outside of the body.
*bladder is a sac-like organ that stores urine before releasing it from the body.
*ureters (YOOR-eh-ters) are tube-like structures that carry urine from the kidneys to the bladder.
*kidneys are the pair of organs that filter blood and remove waste products and excess water from the body in the form
*intestines are the muscular tubes that food passes through during digestion after it exits the stomach.
*anus (A-nus) is the opening at the end of the digestive system, through which waste leaves the body.
Men may have UTIs too, but these infections usually result from something in the urinary tract that blocks the normal
flow of urine from
The organs of the urinary tract, any of which may become the site of infection.
the body, such as a kidney stone* or an enlarged prostate* in older men. In fact, anyone who has a problem with the structure
of the urinary tract or the way it functions is more likely to have UTIs. Urinary catheters* can cause UTIs in either men
or women because bacteria can enter the urinary tract more easily when a catheter is present. For this reason, UTIs
*kidney stone is a hard structure that forms in the urinary tract. This structure is composed of crystallized chemicals
that have separated from the urine. It can obstruct the flow of urine and cause tissue damage and pain as the body attempts
to pass the stone through the urinary tract and out of the body.
*prostate (PRAH-state) is a male reproductive gland located near where the bladder joins the urethra. The prostate produces
the fluid part of semen.
*urinary catheters are thin tubes used to drain urine from the body.
can be a serious problem among patients in hospitals, where catheters are used frequently. UTIs are not contagious, which
means that you cannot catch a UTI from someone who has one. Chlamydia and Mycoplasma bacteria, however, can be transmitted
through sexual intercourse.
What Are the Signs and Symptoms of a UTI?
Some people may not have any symptoms of a UTI, but when the infection occurs, it usually brings with it a burning or
stinging feeling during urination. People with UTIs may feel as if they have to urinate more frequently and more urgently
than usual, but when a person does urinate, sometimes very little comes out. A UTI can make a person feel very tired or feverish;
it also can produce a feeling of pressure in the lower belly in women and a sensation of pressure or fullness in the rectum*
in men. The urine itself can be cloudy or have a bit of blood in it, and it may smell bad. If the bacteria spread to the kidneys
and cause pyelonephritis, the person typically feels very ill, with fever, chills, nausea (NAW-zee-uh), vomiting, and sharp
pain in the back or side.
How Do Doctors Diagnose UTIs?
If a doctor suspects that a patient has a UTI, he or she will ask about the person's symptoms to rule out other conditions.
For example, an allergic reaction to a soap may cause irritation of the urethra that could lead to stinging when a person
urinates, mimicking a UTI. The doctor may take a urine sample and then dip a special strip of paper into it, testing for infection-fighting
white blood cells, protein, nitrates*, and blood, which can all be signs that a UTI might be present. The urine sample will
be examined under a microscope for bacteria and types of white blood cells that might point to infection. To confirm the presence
of a UTI, the urine sample will be cultured*. Any bacteria that grow are tested to see which antibiotics will kill them. This
helps the doctor decide which medication will best treat the UTI.
If an infant has a UTI or if an adult or child has repeated UTIs, the doctor may want to see if there are any problems
in the urinary tract that may be causing or contributing to the infections. The doctor may order tests (such as special X
rays or ultrasound* images of the urinary tract) to take a better look at the shape and function of the kidneys, bladder,
and ureters. If there are any problems, the patient may be referred to a urologist, a doctor who specializes in diagnosing
and treating problems of the urinary tract. The urologist can examine the urethra and bladder with a cystoscope (SIS-tuh-skope),
a special lighted tube with lenses that is inserted into the urethra.
*rectum is the final portion of the large intestine, connecting the colon to the anus.
*nitrates (NYE-trayts) are chemical substances that can be produced by the breakdown of proteins by certain bacteria.
*cultured (KUL-churd) means subjected to a test in which a sample of fluid or tissue from the body is placed in a dish
containing material that supports the growth of certain organisms. Typically, within days the organisms will grow and can
*ultrasound, also called a sonogram, is a diagnostic test in which sound waves passing through the body create images
on a computer screen.
What Is the Treatment for UTIs?
Once a doctor confirms that a bacterial UTI is present, antibiotics are prescribed, which usually clear up the infection.
If the UTI involves the kidneys, this can be a more serious medical problem. Patients with a kidney infection usually need
to be treated in a hospital. Antibiotics and fluids may be given intravenously* until fever disappears and the patient begins
to feel better. Even if they have no symptoms, all men typically are treated if they are found to have a UTI, and so are women
who are pregnant and those who have diabetes* or abnormalities of the urinary tract. Treatment is necessary in these cases
because there is a higher risk of pyelonephritis. Young women who have bacteria in the urine but who do not have symptoms
of a UTI usually do not need treatment.
A person taking antibiotics for urethritis or cystitis usually will feel much better soon after starting the medication.
During the first few days of treatment, a heating pad can help soothe some of the lower belly pain that may come with UTIs.
There are also medicines that ease discomfort during urination. It is important to remember that these medicines do not treat
the infection; they treat only the symptoms of stinging and burning. Doctors advise people with UTIs to take all prescribed
antibiotics, which usually are given for about a week. Taking all of the prescribed medication is necessary even if a patient
begins to feel better right away. Stopping the antibiotics early can mean that the infection will come back, because all the
bacteria may not have been killed. A person with pyelonephritis typically can expect a longer recovery time, possibly up to
several weeks. It is very important that kidney infections be cured completely because they can lead to serious problems,
such as permanent kidney damage, high blood pressure*, and even kidney failure later in life.
Can UTIs Be Prevented?
When it comes to preventing UTIs, practicing good hygiene is a major part of keeping bacteria from entering the urinary
tract. It is wise for men and women to keep the genital*, urinary, and anal areas clean. It is recommended that women wipe
from front to back, from the urinary tract opening to the anus, after going to the toilet.
*intravenously means given or injected directly through a vein.
*diabetes (dye-uh-BEE-teez) is a condition in which the body's pancreas does not produce enough insulin or the body cannot
use the insulin it makes effectively, resulting in increased levels of sugar in the blood. This can lead to increased urination,
dehydration, weight loss, weakness, and a number of other symptoms and complications related to chemical imbalances within
*high blood pressure, also called hypertension, is a condition in which the pressure of the blood in the arteries is above
*genital (JEH-nih-tul) refers to the external sexual organs,
*malformation (mal-for-MAY-shun) is an abnormal formation of a body part.
Doctors advise that people who want to keep UTIs at bay drink plenty of water, which helps flush out the urinary tract.
Going to the bathroom when a person feels the need to go, instead of holding urine in, also can help deter UTIs. Finally,
some foods or drinks (such as acidic fruit juices, like orange juice or grapefruit juice; spicy foods; or foods or drinks
that contain caffeine) can irritate the bladder; it is a good idea for a person with a UTI to avoid them if they cause irritation.
Infants, children, and adults who have UTIs as a result of a malformation* or other problems in the urinary tract are at increased
risk of contracting UTIs in the future. Their doctors may prescribe small doses of antibiotics to take every day for several
months or longer to help prevent infections and possible damage to the kidneys over time.