Urinary tract infection (UTI)

A urinary tract infection (UTI) is a common infection that causes illness in babies and children. It happens when germs get into the urine (wee) and travel into the urinary tract. Some babies and children with UTIs may become irritable, have a fever, have pain when they wee, feel sick or be sick.

The information covers:

  • what a UTI is, and what may cause it
  • how your doctor can find out whether your child has a UTI
  • treatment that your child may need
  • how to help protect your child against UTI
  • monitoring UTI, especially if it keeps coming back or the infection passes to the kidneys

About the urinary system

The urinary system gets rid of things that the body no longer needs, so that we can grow and stay healthy.

  • The kidneys are bean-shaped organs. They filter blood and remove extra water and waste in urine (wee). Most of us have two kidneys. They are at the back on either side of our spine (backbone), near the bottom edge of our ribs.
  • The two ureters are long tubes that carry urine from the kidneys to the bladder.
  • The bladder is a muscular bag that stores urine until we are ready to urinate (wee). It sits low down in the pelvis.
  • The urethra is a tube that carries urine from the bladder to the outside of the body. We urinate through the opening.

About the urinary system and kidneys

UTI symptoms and signs

Urinary tract infection (UTI) is a common bacterial infection that causes illness in babies and children. It may be difficult to recognise UTI because the symptoms (what your child feels or complains about) and signs are non-specific (they could also be seen in a lot of other health conditions), especially in babies and children under 3 years old.

Symptoms are what your child feels or complains about.

Signs are what you, your child or a healthcare professional can see or detect.

Common UTI symptoms and signs in babies and young children

  • Fever (temperature over 38ºC)
  • Being sick (vomiting)
  • Feeling tired (lethargy)
  • Being irritable
  • Poor feeding

Common symptoms and signs in older children

  • Pain or a stinging/burning feeling when passing urine (dysuria)
  • Going to the toilet more often than usual (frequency) or holding on because it is painful to go
  • Wetting the bed more often than usual, or wetting themselves because they cannot get to the toilet in time.

Symptoms and signs of febrile UTI and kidney infection

If your child has a UTI with a fever (febrile UTI) or kidney infection, he or she may have some of the symptoms listed above, as well as some of the following.

  • Fever (temperature over 38ºC) that is constantly spiking (keeps going up) in spite of giving medicines such as paracetamol (including Calpol®)
  • Shaking or shivering (rigor), sometimes with a fever
  • Signs of dehydration (not enough water in the body) – children may be thirstier than usual, and babies may have a soft sunken spot (fontanelle) on their head
  • Pain in the back
  • Blood in the urine (haematuria) – sometimes the urine is coloured red or dark brown
  • Cloudy urine
  • Yellowing of the skin (jaundice) in babies – this is a very rare symptom

If you think that your child may have a UTI, contact your doctor. If you cannot reach your doctor straight away, contact 111 or NHS Direct or your local out-of-hours GP service.


A urinary tract infection (UTI) happens when bacteria (germs) get into the urine and travel into the urinary tract. This causes inflammation (like a swelling) in part of the urinary tract.

Types of UTI

  • A lower UTI is an infections in the lower parts of the urinary tract, the urethra and the bladder. This is called cystitis.
  • An upper UTI is an infection in the upper parts of the urinary tract, especially the kidneys. This is called pyelonephritis.

How common are UTIs in children?

UTI is a common infection in babies and children. It is more common in girls. It is estimated that:

  • one out of 10 girls will have had a UTI by the age of 16 years
  • one out of 30 boys will have had a UTI by the age of 16 years
  • about one out of 50 babies and young children ill have had a UTI by the age of 2 years

Recurrent UTIs

Some children have recurrent UTIs, which keep coming back even after proper treatment.

These children often have other problems with their urinary system, such as vesicoureteral reflux (VUR). As children with VUR urinate, some urine refluxes (goes back up) towards the kidneys. This makes it easier for germs that cause UTI to travel all the way up to the kidneys, where they cause a more serious infection and illness.

Tests and diagnosis

If you think that your child may have a UTI, take him or her to your doctor. They can find out if there is a UTI by doing a urine test and finding out about their symptoms.


Your child’s UTI will need to be treated with antibiotics, medicines that kill bacteria. Early treatment may reduce the likelihood of your child becoming acutely unwell and needing to be admitted to hospital.

More information about UTI treatment


There are some things that you and your child can do help prevent or reduce the frequency of UTIs:

  • Encourage your child to go to the toilet regularly – every 3 to 4 hours during the day, before having a bath and before going to bed
  • Change your baby’s nappies regularly.
  • Help your child avoid constipation – speak with your doctor or nurse for more information.
  • Make sure your child drinks plenty of fluids, especially water, eats a healthy diet, is active and gets regular sleep.

More information about UTI prevention

About the future

Children who are treated for UTIs with antibiotics usually get better. In most children the UTI does not keep coming back, and there is very little risk of long-term problems.

A few children need to have follow-up appointments or further treatment.