What Is a Urinary Tract Infection?
A
urinary tract infection is an infection that occurs anywhere in the urinary tract. Your urinary tract is made up of organs that:
- Collect urine
- Store urine
- Release urine from your body.
These organs include the kidneys, ureters, bladder, and urethra.
A urinary tract infection is a serious health problem that affects millions of people each year. Urinary tract infections are the second most common type of infection in the body, and they account for about 8.3 million doctor visits each year. Urinary tract infections are more common in women than men -- approximately 20 percent of women will develop a urinary tract infection at some point in their lives. Although urinary tract infections in men are not as common, they can be very serious when they occur
(see UTI in Men for more information).
Understanding the Urinary Tract
The urinary tract consists of the kidneys, ureters, bladder, and urethra. The kidneys are two bean-shaped organs located below the ribs toward the middle of the back. The role of the kidneys is to:
- Help control blood pressure
- Make red blood cells
- Keep bones strong
- Remove extra water and wastes from the blood
- Convert the wastes to urine.
The wastes in your blood come from the normal breakdown of active muscle and from the food that you eat. Your body uses the food for energy and self-repair and sends the wastes to the blood. If your kidneys did not remove these wastes, the wastes would build up in the blood and damage your body.
Narrow tubes called ureters carry urine from the kidneys to the bladder, which is an oval-shaped chamber in the lower abdomen. Like a balloon, the bladder's elastic walls stretch and expand to store urine and flatten back together when the urine is emptied through the urethra outside of the body.
Other Names for a Urinary Tract Infection
A
urinary tract infection is also known as a
UTI. A urinary tract infection in the urethra is called urethritis. A
UTI that causes a bladder infection (bacteria move to the bladder and multiply) is called cystitis. A UTI that causes a kidney infection (bacteria move to the kidneys) is called
pyelonephritis.
What Causes a Urinary Tract Infection?
In most cases, a urinary tract infection is caused by bacteria, which live in the digestive tract, the vagina, or around the urethra (the entrance to the urinary tract). A urinary tract infection can occur when the bacteria enter the urethra and travel to the bladder and kidneys. Although your body usually removes the bacteria, some people seem to be prone to infection.
Doctors can seldom explain why one person will get a urinary tract infection and another person will not. However,
urinary tract infection research has shown that people with certain risk factors are more likely than others to develop a urinary tract infection. A risk factor is anything that increases a person's chance of developing a disease.
Urinary tract infection risk factors include:
- Wiping from back to front after a bowel movement (BM), which allows germs to get into your urethra.
- Having sexual intercourse can cause germs in the vagina to be pushed into the urethra.
- Waiting too long to pass urine. When urine stays in the bladder for a long time, more germs are made.
- Using a diaphragm for birth control, using spermicide with a diaphragm, or using spermicide on a condom.
- Anything that makes it hard to completely empty your bladder, like kidney stones.
- Having diabetes, which makes it harder for your body to fight other health problems.
- Loss of estrogen and changes in the vagina after menopause.
What Are the Signs and Symptoms?
- Pain or stinging when you pass urine
- Frequent or intense urges to urinate, even when you have little urine to pass
- Pressure in your lower belly or back
- Urine that smells bad or looks milky, cloudy, or reddish in color
- Fever or chills.
Not everyone with a urinary tract infection will develop symptoms. Children who have urinary tract infections are more likely to have a fever and no other symptoms, which often results in a misdiagnosis.
In order to diagnose a patient with a urinary tract infection, doctors will perform a physical exam and ask the following questions:
- How much fluid do you drink?
- Do you feel pain or a burning sensation when you urinate?
- Do you have difficulty urinating?
- (For women) What type of birth control do you use?
Other procedures that will help your doctor make a diagnosis include:
- A urine test
- An x-ray or an ultrasound of the patient's kidneys
- An exam that looks into the patient's bladder with an instrument called a cystoscope.
Urine Tests
A urine test is needed to check for bacteria and infection-fighting cells. Your doctor may also order a urine culture, which is a test that allows bacteria from the urine to grow in a lab dish. This culture allows doctors to prescribe the correct medicine that is needed for the specific type of bacteria.
Images
X-rays, sound waves (ultrasound), or a computed tomography (CT) scan will allow your doctor to view your bladder or kidneys. These pictures can show stones, blockages, or swelling.
Cystoscopy
During a
cystoscopy, the urethra and bladder can be seen from the inside with a cystoscope, which is a thin tube that has lenses like a microscope. The doctor will insert the tube into the urinary tract through the urethra.
Once it is determined that your symptoms have been caused by a
urinary tract infection, your doctor will prescribe an antibiotic, which can kill the bacteria that are causing the urinary tract infection.
For a simple urinary tract infection, treatment will entail 3 days of antibiotics. For more serious urinary tract infections, treatment will entail 7 days or more of antibiotics. Patients should be sure to tell their doctors if they are allergic to any medications.
If a urinary tract infection is not treated, it can affect other parts of the body. Patients who are pregnant and have signs of a urinary tract infection should see their doctor right away. A urinary tract infection can cause problems with your pregnancy, such as early delivery or
high blood pressure.
Chronic Urinary Tract Infections
However, about 1 out of every 5 women who get a urinary tract infection will get another one. Men and patients with
diabetes or other problems that make it difficult to urinate may be at a greater risk of developing a
UTI.
Patients who get recurrent urinary tract infections should talk with their doctor about special bladder infection treatment plans. Doctors may refer patients to an urologist, who is a doctor who specializes in urinary problems. Patients who have chronic urinary tract infections may have to take antibiotics over a longer period to help prevent repeat infections.
Men who have urinary tract infections may need to take antibiotics for a longer period of time because bacteria can hide deep in the prostate tissue. It is important for men to see their doctor for treatment that fits their needs.
Preventing a Urinary Tract Infection
There are steps you can take to prevent a urinary tract infection. However, even if you follow these steps you can still get a urinary tract infection.
Suggestions for preventing a urinary tract infection include:
- Drinking plenty of fluid, especially water, to flush the bacteria from your system. Aim for 6 to 8 glasses a day.
- Drinking cranberry juice and taking vitamin C, both of which increase the acid in your urine so bacteria can't grow easily. Cranberry juice also makes your bladder wall slippery, so bacteria can't stick to it.
- Urinating frequently and going when you first feel the urge. Bacteria can grow when urine stays in the bladder too long.
- Urinating shortly after sex. This can flush away bacteria that might have entered your urethra during sex.
- Always wiping from front to back after using the toilet, especially after a bowel movement.
- Wearing cotton underwear and loose-fitting clothes so that air can keep the area dry. Avoid tight-fitting jeans and nylon underwear, which trap moisture and can help bacteria grow.
- Switching forms of birth control. For women, using a diaphragm or spermicide for birth control can lead to a UTI because it may increase bacteria growth. Patients who have trouble with urinary tract infections should consider modifying their birth control method.
- Discontinuing use of unlubricated or spermicidal condoms. Using unlubricated condoms or spermicidal condoms increases irritation, which allows bacteria to grow. Patients who have trouble with urinary tract infections should consider switching to lubricated condoms without spermicide or using a nonspermicidal lubricant.
