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, which 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:
- Pain in the flank (side), abdomen or pelvic area
- Pressure in the lower pelvis
- Frequent need to urinate (frequency)
- Painful urination (dysuria)
- Urgent need to urinate (urgency)
- Incontinence (urine leakage)
- The need to urinate at night
- Abnormal urine color (cloudy urine)
- Blood in the urine
- Strong or foul-smelling urine
Other symptoms that may be associated with a urinary tract infection include:
- Pain during sex
- Penis pain
- Flank (side of the body) pain
- Fatigue
- Fever (temperature above 100oF)
- Chills
- Vomiting
- Mental changes or confusion
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 two out
of every 100 people. One percent to 2 percent 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 (ie, 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 significant history of
urinary tract infections, you may be given a prescription for antibiotics that
you would take when symptomatic. Other patients may be given antibiotics
to take every day or every other day to prevent them. 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:
- Good hygiene of the genital area—especially in women—may help reduce the
chances of introducing bacteria into the urethra. 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.
- Urinating frequently, which flushes bacteria out of the bladder, may
reduce the risk of cystitis in those who are prone to urinary tract
infections. Drinking plenty of fluids encourages frequent urination. Avoid
fluids that irritate the bladder, such as alcohol, citrus juices and drinks
containing caffeine.
- Urinating immediately after sex may help flush out bacteria that may
have been introduced during intercourse.
- Applying an estrogen-containing vaginal cream in post-menopausal women
to reduce the risk of a urinary tract infection.
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.
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This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition. This document was last reviewed on: 12/15/2008...#9135
