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Urinary Tract Infections

Medically reviewed by: T. Ernesto Figueroa, MD

What Is a Urinary Tract Infection?

A bacterial urinary tract infection (UTI) is the most common kind of infection affecting the urinary tract. Urine, or pee, is the fluid that kidneys filter out of the bloodstream. Pee contains salts and waste products, but it doesn't normally contain bacteria. When bacteria get into the bladder or kidney and multiply in the pee, a UTI can happen.

There are three main types of UTI. Bacteria that infect only the urethra (the short tube that delivers pee from the bladder to the outside of the body) cause urethritis (pronounced: yur-ih-THRY-tis). Bacteria can also cause a bladder infection, which is called cystitis (pronounced: sis-TIE-tis). Another, more serious kind of UTI is infection of the kidney itself, known as pyelonephritis (pronounced: pie-low-nih-FRY-tis). With this type of UTI, a person often has back pain, high fever, and vomiting.

The most common type of UTI is cystitis. These mostly just cause discomfort and inconvenience. Bladder infections can be quickly and easily treated. And it's important to get treatment promptly to avoid the more serious infection that reaches the kidneys.

What Causes Urinary Tract Infections?

UTIs usually happen because bacteria enter the urethra, then make their way up into the bladder and cause an infection. Girls get UTIs much more often than guys, most likely due to differences in the shape and length of the urethra. Girls have shorter urethras than guys, and the opening lies closer to the anus (where poop comes out) and the vagina, where bacteria are likely to be.

Bacteria can get into the urethra several ways. During sex, for example, bacteria in the vaginal area may be pushed into the urethra and eventually end up in the bladder, where pee provides a good environment for the bacteria to grow. This is why females who are sexually active often get UTIs. (UTIs are not contagious, so you can't catch a urinary tract infection from someone else.)

Bacteria may also get into a girl's bladder if she wipes from back to front after a bowel movement (BM), which can contaminate the urethral opening. The use of spermicides (including condoms treated with spermicide) and diaphragms as contraceptives also may increase the risk of UTIs.

Sexually transmitted diseases (STDs) may cause UTI-like symptoms, such as pain with peeing. This is due to the inflammation and irritation of the urethra or vagina that's sometimes associated with chlamydia and other STDs. If untreated, STDs can lead to serious long-term problems, including pelvic inflammatory disease (PID) and infertility. Unlike UTIs, STDs are contagious.

Some people seem to get frequent UTIs, but they often have other problems that make them more likely to get an infection, like a problem in the urinary tract structures or function. The most common functional problem of the urinary tract is vesicoureteral reflux (pronounced: veh-zi-coe-you-REE-tur-al), a condition in which some pee flows backward, or refluxes, from the bladder into the ureters and even up to the kidneys.

What Are the Signs & Symptoms of UTIs?

UTIs can cause such signs as:

  • pain, burning, or a stinging sensation when peeing
  • an increased urge or more frequent need to pee (though only a very small amount of pee may be passed)
  • fever
  • waking up at night a lot to go to the bathroom
  • belly pain in the area of the bladder (generally below the belly button)
  • foul-smelling pee that may look cloudy or contain blood

If you have any symptoms of a UTI, you'll need to go to a doctor right away. The sooner you begin treatment, the less uncomfortable you'll be. Call your doctor's office or clinic. If you can't reach your doctor, you can visit an urgent care center or hospital emergency room. The most important thing is to take action as soon as possible.

How Are UTIs Diagnosed?

Only a health care provider can treat urinary tract infections. The first thing a doctor will do is confirm that a person has a UTI by taking a clean-catch urine specimen. At the doctor's office, you'll be asked to clean your genital area with disposable wipes and then pee into a sterile (bacteria-free) cup.

The sample may be used for a urinalysis (a test that microscopically checks the pee for germs or pus) or a urine culture (to grow and identify bacteria in a lab). Knowing what bacteria are causing the infection can help your doctor choose the best treatment.

How Are UTIs Treated?

UTIs are treated with antibiotics. After several days of antibiotics, your doctor may repeat the urine tests to be sure that the infection is gone. It's important to make sure of this because an incompletely treated UTI can come back or spread.

If someone has a lot of pain from a UTI, the doctor may recommend a medicine to help relieve the spasm and pain in the bladder. This will turn pee a bright orange color, but it's harmless and will usually make a person much more comfortable within hours. In the case of a kidney infection, a doctor may prescribe pain medicine.

If you've finished all the medicine or if your symptoms aren't much better after 2 to 3 days of treatment, contact your doctor.

Drink lots of water during and after treatment because each time you pee, the bladder cleanses itself a little bit more. Cranberry juice may also be helpful. Skip drinks that containe caffeine (which can irritate the bladder), such as soda and iced tea.

People who get a doctor's help for a UTI right away should be clear of symptoms within a week. Someone with a more severe infection may need treatment in a hospital so they can get antibiotics by injection or IV (intravenously, given into a vein right into the bloodstream).

A doctor may tell people with UTIs to avoid sex for a week or so, which lets the inflammation clear up completely.

Can UTIs Be Prevented?

A few things can help prevent UTIs. After peeing, girls should wipe from front to back with toilet paper. After BMs, wipe from front to back to avoid spreading bacteria from the rectal area to the urethra.

Also, go to the bathroom when needed and don't hold the pee in. Pee that stays in the bladder gives bacteria a good place to grow.

Keep the genital area clean and dry. Girls should change their tampons and pads regularly during their periods. Bubble baths can irritate the vaginal area, so girls should take showers or plain baths. Avoid long exposure to moisture in the genital area by not wearing nylon underwear or wet swimsuits. Wearing underwear with cotton crotches is also helpful. Skip using feminine hygiene sprays or douches, as these can irritate the urethra.

If you are sexually active, go to the bathroom both before and within 15 minutes after sex. After sex, gently wash the genital area to remove any bacteria. Avoid sexual positions that irritate or hurt the urethra or bladder. Couples who use lubrication during sex should use a water-soluble lubricant such as K-Y Jelly.

Finally, drinking lots of water each day keeps the bladder active and bacteria-free.

UTIs are uncomfortable and often painful, but they're common and easily treated. The sooner you contact your doctor, the sooner you'll be able to get rid of the problem.

Medically reviewed by: T. Ernesto Figueroa, MD
Date reviewed: October 2021