When Your Child Has a Urinary Tract Infection (UTI)

A urinary tract infection (UTI) is most often caused by bacteria. The urinary tract includes the kidneys, ureters, bladder, and urethra. Children often get UTIs in the bladder. This is called cystitis. They can also get UTIs that affect the kidneys. This is called pyelonephritis. A UTI can be painful. But with treatment, most children recover fine.

What is the urinary tract?

These body parts make up the urinary tract:

  • Kidneys. These 2 organs filter waste from the blood and make urine.

  • Ureters. These 2 tubes carry urine from the kidneys to the bladder.

  • Bladder. This is the pouch that stores urine.

  • Urethra. This tube carries urine from the bladder to outside the body when you pee.

Outline of girl's lower body showing kidneys, ureters, bladder, and urethra. Closeup of outline of boy's lower body showing bladder, urethra, and penis.

What causes a UTI?

Most UTIs are caused by bacteria. It gets into the urinary tract through the urethra. The urinary tracts of boys and girls are a bit different. The urethra is shorter in girls. This makes it easier for bacteria to enter. As a result, girls are more likely than boys to get UTIs. Other causes of UTI include:

  • Not emptying the bladder fully

  • Not keeping the area clean

  • Trouble pooping enough (constipation)

  • Tight foreskin on the penis

  • Urine that flows back up the ureters (vesicoureteral reflux)

  • Birth defects of the urinary system

Sometimes the cause of a UTI is unknown.

What are the symptoms of a UTI?

A UTI in the bladder (cystitis) has symptoms such as:

  • Pain when peeing

  • Peeing often

  • Urgent need to pee

  • Blood in the urine

  • New daytime wetting or nighttime bedwetting

A UTI in the kidneys (pyelonephritis), has the same symptoms. But it can also include:

  • Fever

  • Belly (abdominal) pain

  • Upset stomach (nausea) and vomiting

  • Cloudy urine

  • Strong-smelling urine

How is a UTI diagnosed?

The healthcare provider will ask about your child’s symptoms and health history. They will give your child an exam.

You will need to help your child give a pee (urine) sample. The urine is checked for bacteria and other signs of infection. The urine is also sent for a culture. This is a test that shows what kind of bacteria is in the urine. It can take 1 to 3 days to get results of a urine culture. If the provider thinks your child has a UTI, they will likely start treatment before the results of the culture come back.

If your child has severe symptoms, they may need other tests. You will be told more about this, if needed.

How is a UTI treated?

The healthcare provider will prescribe antibiotic medicine for your child. Make sure your child takes all of the medicine. They need to take it even when they start feeling better. Symptoms of a UTI usually go away within 24 to 72 hours of starting treatment.

To help ease your child’s symptoms:

  • Give your child over-the-counter (OTC) medicines, such as ibuprofen or acetaminophen, to manage pain and fever. Don't give ibuprofen to a baby who is younger than 6 months old, or to a child who is dehydrated or constantly vomiting. Don’t give aspirin (or medicine that contains aspirin) to a child younger than age 19 unless directed by your child’s provider. Taking aspirin can put your child at risk for Reye syndrome. This is a rare but very serious disorder. It most often affects the brain and the liver.

  • Ask the provider about medicines that can ease pain when peeing.

  • Give your child plenty of fluids to drink. Cranberry juice may help ease some pain.

For follow-up care:

  • If a urine culture was done, call for the results from the healthcare provider.

  • Make an appointment about 1 week after your child has finished the antibiotic medicine.

When to call the healthcare provider

Call the healthcare provider if your child has any of these:

  • Symptoms that don't get better within  48 hours of starting treatment

  • Fever (see "Fever and children" below)

  • A fever that goes away but returns after starting treatment

  • Worse belly or back pain

  • Signs of dehydration, such as very dark or little urine, a lot of thirst, dry mouth, or dizziness

  • Vomiting

  • Trouble taking the antibiotic medicine

  • Child starts acting sicker

How is a UTI prevented?

  • Make sure your child drinks plenty of fluids.

  • Tell your child to empty their bladder fully when peeing.

  • Teach girls to wipe from front to back when using the bathroom.

  • Don't bathe them in bubble bath.

  • Make sure your child does not get constipated. Talk with their provider for help if constipation is a problem.

In some cases, a child may need ultrasound of the kidneys and bladder. This is a painless test. It helps the healthcare provider look for anatomy problems that could cause a UTI. If problems are found, or if your child has repeated UTIs, more imaging tests may be needed.

Fever and children

Use a digital thermometer to check your child’s temperature. Don’t use a mercury thermometer. There are different kinds and uses of digital thermometers. They include:

  • Rectal. For children younger than 3 years, a rectal temperature is the most accurate.

  • Forehead (temporal). This works for children age 3 months and older. If a child under 3 months old has signs of illness, this can be used for a first pass. The provider may want to confirm with a rectal temperature.

  • Ear (tympanic). Ear temperatures are accurate after 6 months of age, but not before.

  • Armpit (axillary). This is the least reliable but may be used for a first pass to check a child of any age with signs of illness. The provider may want to confirm with a rectal temperature.

  • Mouth (oral). Don’t use a thermometer in your child’s mouth until they are at least 4 years old.

Use a rectal thermometer with care. Follow the product maker’s directions for correct use. Insert it gently. Label it and make sure it’s not used in the mouth. It may pass on germs from the stool. If you don’t feel OK using a rectal thermometer, ask the healthcare provider what type to use instead. When you talk with any healthcare provider about your child’s fever, tell them which type you used.

Below is when to call the healthcare provider if your child has a fever. Your child’s healthcare provider may give you different numbers. Follow their instructions.

When to call a healthcare provider about your child’s fever

For a baby under 3 months old:

  • First, ask your child’s healthcare provider how you should take the temperature.

  • Rectal or forehead: 100.4°F (38°C) or higher

  • Armpit: 99°F (37.2°C) or higher

  • A fever of ___________as advised by the provider

For a child age 3 months to 36 months (3 years):

  • Rectal or forehead: 102°F (38.9°C) or higher

  • Ear (only for use over age 6 months): 102°F (38.9°C) or higher

  • A fever of ___________ as advised by the provider

In these cases:

  • Armpit temperature of 103°F (39.4°C) or higher in a child of any age

  • Temperature of 104°F (40°C) or higher in a child of any age

  • A fever of ___________ as advised by the provider

Online Medical Reviewer: Donna Freeborn PhD CNM FNP
Online Medical Reviewer: Liora C Adler MD
Online Medical Reviewer: Raymond Kent Turley BSN MSN RN
Date Last Reviewed: 5/1/2022
© 2000-2024 The StayWell Company, LLC. All rights reserved. This information is not intended as a substitute for professional medical care. Always follow your healthcare professional's instructions.