Urinary tract infections (UTIs) are common in kids. They happen when bacteria (germs) get into the bladder or kidneys.

A baby with a UTI may have a fever, throw up, or be fussy. Older kids may have a fever, have pain when peeing, need to pee a lot, or have lower belly pain.

Kids with UTIs need to see a doctor. These infections won't get better on their own. UTIs are easy to treat and usually clear up in a week or so.

Taking antibiotics kills the germs and helps kids get well again. To be sure antibiotics work, you must give all the prescribed doses — even when your child starts feeling better.

What Are the Signs & Symptoms of a UTI?

Most UTIs happen in the lower part of the urinary tract — the urethra and bladder. This type of UTI is called cystitis. A child with cystitis may have:

• 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
• wetting problems, even though the child is potty trained
• belly pain in the area of the bladder (generally below the belly button)
• foul-smelling pee that may look cloudy or contain blood

An infection that travels up the ureters to the kidneys is called pyelonephritis (pie-low-nih-FRY-tis) and is usually more serious. It causes many of these same symptoms, but the child often looks sicker and is more likely to have a fever (sometimes with shaking chills), pain in the side or back, severe tiredness, or vomiting.

What Causes UTIs?

UTIs are much more common in girls because a girl's urethra is shorter and closer to the anus (where poop comes out). Uncircumcised boys younger than 1 year also have a slightly higher risk for a UTI.

Other risk factors for a UTI include:

• a problem in the urinary tract (for example, a malformed kidney or a blockage somewhere along the tract of normal urine flow)
• an abnormal backward flow (reflux) of urine from the bladder up the ureters and toward the kidneys. This is known as vesicoureteral reflux (VUR), and many kids with a UTI are found to have it.
• poor toilet and hygiene habits
• family history of UTIs

UTIs are easy to treat, but it's important to catch them early. Undiagnosed or untreated UTIs can lead to kidney damage.

How Are UTIs Diagnosed?

To diagnose a UTI, health care providers ask questions about what's going on, do an exam, and take a sample of pee for testing.

How a sample is taken depends on a child's age. Older kids might simply need to pee into a sterile cup. For younger children in diapers, a catheter is usually preferred. This is when a thin tube is inserted into the urethra up to the bladder to get a "clean" urine sample.

The sample may be used for a urinalysis (a test that microscopically checks the urine for germs or pus) or a urine culture (which attempts to grow and identify bacteria in a laboratory). 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 a child has severe pain when peeing, the doctor may also prescribe medicine that numbs the lining of the urinary tract. (This medicine temporarily causes the pee to turn orange.)

Give prescribed antibiotics on schedule for as many days as your doctor directs. Keep track of your child's trips to the bathroom, and ask your child about symptoms like pain or burning during peeing. These symptoms should improve within 2 to 3 days after antibiotics are started.

Encourage your child to drink plenty of fluids, but skip drinks that containe caffeine (which can irritate the bladder), such as soda and iced tea.

Most UTIs are cured within a week with treatment.

Treatment for More Severe UTIs

Kids 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).

This might happen if:

• the child has high fever or looks very ill, or a kidney infection is likely
• the child is younger than 6 months old
• bacteria from the infected urinary tract may have spread to the blood
• the child is dehydrated or is vomiting and cannot take any fluids or medicine by mouth

Kids with VUR will be watched closely by the doctor. VUR might be treated with medicines or, less commonly, surgery. Most kids outgrow mild forms of VUR, but some can develop kidney damage or kidney failure later in life.

Can UTIs Be Prevented?

These tips can help prevent UTIs:

• In infants and toddlers, change diapers often to help prevent the spread of bacteria that cause UTIs. When kids are potty trained, it's important to teach them good hygiene. Girls should know to wipe from front to rear — not rear to front — to prevent germs from spreading from the anus to the urethra.
• School-age girls should avoid bubble baths and strong soaps that might cause irritation. They also should wear cotton underwear instead of nylon because it's less likely to encourage bacterial growth.
• All kids should be taught not to "hold it" when they have to go. Pee that stays in the bladder gives bacteria a good place to grow.
• Kids should drink plenty of fluids but avoid those with caffeine.

When Should I Call the Doctor?

Call the doctor right away if your child has an unexplained fever with shaking chills, especially if there's also back pain or any type of pain when peeing.

Also call if your child has any of these:

• bad-smelling, bloody, or discolored pee
• low back pain or belly pain (especially below the belly button)
• a fever of over 101°F (38.3°C) in children or 100.4°F (38°C) rectally in infants

Call the doctor if your infant has a fever, feeds poorly, vomits repeatedly, or seems unusually irritable.