Most urinary tract infections (UTIs) in children are caused by bacteria that normally live in the digestive system getting into the urethra (the tube that carries urine out of the body).

In young children, bacteria can enter the urethra when they wipe their bottom after going to the toilet, and soiled toilet paper comes into contact with their genitals.

This is more of a problem for girls than boys, because girls’ bottoms are much nearer the urethra.

Babies who soil their nappies can also sometimes get small particles of stool into their urethra, particularly if they squirm a lot when being changed.

Increased risk

There is usually no obvious reason why some children develop UTIs and others do not.

However, some children may be more vulnerable to UTIs due to a problem with bladder emptying. Normally, we empty our bladder completely when going to the toilet. If urine is left in the bladder, it can allow bacteria to grow and an infection to develop.

Problems that can affect bladder emptying include:

• constipation – this can sometimes cause part of the large intestine to swell, which can put pressure on the bladder and prevent it from emptying normally
• dysfunctional elimination syndrome – a relatively common childhood condition where a child “holds on” to their urine, even though they have the urge to urinate
• vesicoureteral reflux – an uncommon condition where urine leaks back up from the bladder into the ureters (the tubes connecting the kidneys and bladder) and kidneys. This occurs due to a problem with the valves in the ureters, where they enter the bladder

If your child has symptoms of a urinary tract infection (UTI), a sample of their urine will be tested.

Your GP may also carry out a physical examination of your child and ask if they have a history of bladder or kidney problems.

This will help your GP identify what is causing the infection and determine whether it is in the lower or upper part of the urinary tract.

Collecting a urine sample

You may be asked to collect the urine sample yourself, or a doctor or nurse at your GP surgery may help you. If your child is less than three months old, your GP may refer you straight to hospital to see a paediatrician (a specialist in caring for children) without asking for a urine sample.

Collecting a urine sample from a child can sometimes be difficult, especially in babies and young children. If you are not sure what to do or need some help in collecting the urine sample, ask a doctor or nurse for advice.

In young children who are toilet trained, you will usually be asked to collect a urine sample using a sterile bottle provided by your GP surgery. Collect a sample by holding the bottle in the stream of urine while your child is urinating. Make sure nothing touches the open rim of the bottle, as this could affect the result.

If you are unable to collect a clean sample, it may be collected using a special absorbent pad that you put in your baby’s nappy. A urine sample is then sucked out of the pad using a syringe.

If a urine sample is very difficult to collect at home or in a GP surgery, you may need to go to a hospital. In such cases, a urine sample can be obtained by inserting a small plastic tube called a catheter into your child’s urethra.

Further tests

In many cases, treatment will start soon after a urine sample has been taken, and your child will not need to have any further tests.

However, there are some circumstances where further tests may be carried out, including if:

• your child is less than six months old
• there is no improvement in your child’s symptoms within 24 to 48 hours of treatment
• your child has any unusual symptoms, such as reduced urine flow, high blood pressure (hypertension), or a noticeable lump or mass in their tummy (abdomen) or bladder
• your child has repeated UTIs

In these cases, doctors may recommend carrying out some scans to look for any abnormalities.

Scans

There are many different scans that may be carried out to check for problems in your child’s urinary tract, including:

• an ultrasound scan – where sound waves emitted by a special probe move over your child’s skin and are used to build up a picture of the inside of their body
• a dimercaptosuccinic acid (DMSA) scan – where your child is injected with a slightly radioactive substance called DMSA that shows up on a special device called a gamma camera. This takes pictures of your child’s kidneys; after the scan, the DMSA will pass harmlessly out of your child’s body, in their urine
• a micturating cystourethrogram (MCUG) – where a catheter is used to pass a special type of liquid (contrast agent) that shows up clearly on X-rays into your child’s bladder, while a series of X-rays are taken; as with the DMSA scan, the contrast agent will pass harmlessly out of your child’s body, in their urine

The type of scans used and when they are carried out will depend on your child’s specific circumstances. In some cases, these scans may be carried out a few weeks or months after your child originally developed the infection.

Urinary tract infections (UTIs) are fairly common, but not usually serious, and can be effectively treated with antibiotics.

The urinary tract is where our bodies make and get rid of urine. It comprises the kidneys, and stretches out to the ureters (the tubes connecting the kidneys to the bladder), down to the bladder, and finally the urethra (the tube that carries urine out of the body).

Infections of the kidneys (pyelonephritis) or ureters are known as upper UTIs. Infections of the bladder (cystitis) or infections of urethra (urethritis) are known as lower UTIs.

Upper UTIs are potentially more serious because there is a chance they could lead to long-term problems such as kidney scarring and high blood pressure (hypertension). However, the risk of these problems is low if the infection is treated promptly.

Signs and symptoms

It can be difficult to tell whether a child has a UTI, because the symptoms can be vague and young children cannot easily communicate how they feel.

Signs that your child may have an UTI can include:

• a high temperature (fever)
• vomiting
• tiredness
• irritability
• pain or a burning sensation when urinating
• needing to urinate frequently
• wetting themselves or their bed, having previously been dry
• pain in their tummy (abdomen), side or lower back
• unpleasant smelling urine
• blood in their urine

Read more about the symptoms of UTIs in children.

When to seek medical advice

If you think your child is unwell and could have a UTI, contact your GP as soon as possible.

This is not normally a serious type of infection, but it should be diagnosed and treated quickly to reduce the duration of infection and any risk of complications.

Your GP should be able to diagnose your child with a UTI by asking about their symptoms, examining them and arranging for a sample of their urine to be tested for signs of an infection.

Read more about diagnosing UTIs in children.

What causes UTIs in children?

Most UTIs in children are caused by bacteria from the digestive system entering the urethra.

There are many ways this can happen, but it often occurs when a child wipes their bottom, and soiled toilet paper comes into contact with their genitals. This is more of a problem for girls than boys, because girls’ bottoms are much nearer the urethra.

There is often no obvious reason why some children develop UTIs and others do not, although it can sometimes occur due to a problem affecting the flow of urine through the urinary system. This can lead to a build-up of urine that bacteria can get into more easily.

For example, UTIs are more common in children with:

• constipation, as this can place pressure on their bladder and prevent it from draining normally
• problems with the valves in their ureters, as this can mean urine flows the wrong way up the urinary tract

Read more about the causes of UTIs in children.

Who is affected

UTIs are a relatively common infection during childhood.

They are more common in boys up to the age of six months old, but after this tend to be more common in girls. It is estimated that around 1 in 10 girls and 1 in 30 boys will have had a UTI by the time they turn 16.

How UTIs in children are treated

Most childhood UTIs will clear up within 24 to 48 hours of treatment with antibiotics and won’t cause any long-term problems.

In many cases, treatment will involve your child taking antibiotic tablets at home. For lower UTIs, a three-day course of antibiotics is usually recommended. For upper UTIs, a 7 to 10-day course of antibiotics is usually recommended.

As a precaution, babies under three months old and children with more severe symptoms are usually admitted to hospital for a few days to receive antibiotics directly into a vein (intravenous antibiotics).

Read more about treating UTIs in children.

Can UTIs in children be prevented?

It isn’t possible to prevent all childhood UTIs, but there are some things you can do to reduce your child’s risk, such as:

• encouraging girls to wipe their bottom from front to back and boys to clean around their foreskin regularly
• making sure your child drinks enough and goes to the toilet regularly
• buying loose-fitting cotton underwear for your child instead of underwear made from nylon or other synthetic materials
• include enough fibre in your child’s diet to help prevent constipation

If your child has a problem in their urinary tract that increases their risk of UTIs, such as faulty valves that allow urine to flow the wrong way, they may be prescribed low-dose antibiotics as a long-term measure to prevent further infections.

Read more about preventing UTIs in children.

It isn’t possible to prevent all childhood urinary tract infections (UTIs), but there are some things you can do to reduce the risk of your child getting one.

The following advice may help:

• If possible, exclusively breastfeed your baby for the first six months after they are born – this can help improve your baby’s immune system and reduce their risk of constipation.
• Encourage girls to wipe their bottom from front to back – this will help to minimise the chances of bacteria entering the urethra (the tube through which urine passes).
• Make sure your child is well hydrated and goes to the toilet regularly, as not urinating regularly and “holding in” urine can make it easier for bacteria to infect the urinary tract.
• Avoid nylon and other types of synthetic underwear, as these can help promote the growth of bacteria – loose-fitting cotton underwear should be worn instead.
• Avoid using scented soaps or bubble baths, as these can increase your child’s risk of developing a UTI.
• Take steps to reduce your child’s risk of constipation – make sure they drink enough to keep their urine pale and clear during the day, and speak to your GP about medications that can help if constipation is a persistent problem. Read more about how to prevent constipation.

Some people feel that drinking cranberry juice, or taking cranberry supplements, can help reduce their risk of UTIs. However, recent high-quality research into these claims found little evidence to suggest cranberries do have a significant impact on your chances of developing a UTI.

Recurrent UTIs

A small number of children have recurring UTIs. If your child has previously had a UTI, it is important that both of you watch for the return of any associated symptoms.

Tell your GP of any symptoms as soon as possible, so a diagnosis can be confirmed and treatment can begin.

If your child has a problem in their urinary tract that increases their risk of UTIs, such as faulty valves that allow urine to flow the wrong way, they may be prescribed low-dose antibiotics as a long-term measure to prevent further infections.

The Map of Medicine is used by doctors throughout the NHS to determine the best treatment options for their patients. NHS Choices offers everyone in England exclusive and free access to this cutting-edge internet resource, which lets you see exactly what your doctor sees.

The information in the Map has been approved by the UK’s leading clinical experts, is based on the best available clinical evidence, and is continually updated. To take advantage of this unique resource go to:

Map of Medicine: UTI in children

It can be difficult to tell whether a child has a urinary tract infection (UTI), because the symptoms can be vague and young children cannot easily communicate how they feel.

General signs that may suggest your child is unwell include:

• a high temperature (fever)
• vomiting
• tiredness and lack of energy (lethargy)
• irritability
• poor feeding
• not gaining weight properly
• in very young children, yellowing of the skin and whites of the eyes (jaundice)

More specific signs that your child may have a UTI include:

• pain or a burning sensation when urinating
• needing to urinate frequently
• deliberately holding in their urine
• a change in their normal toilet habits, such as wetting themselves or wetting the bed
• pain in their tummy (abdomen), side or lower back
• unpleasant smelling urine
• blood in their urine
• cloudy urine

When to seek medical advice

If you think your child is unwell and could have a UTI, contact your GP as soon as possible.

Most UTIs in children are not a cause for serious concern, but it’s important for them to be diagnosed and treated promptly to reduce the duration of infection and any risk of complications.

Read more about diagnosing UTIs in children.

Most urinary tract infections (UTIs) in children can be effectively treated with antibiotic medication.

This medication can often be given at home, although there are some situations where it may be necessary for your child to stay in hospital for a few days.

Treatment at home

If your child is over three months old and are not thought to be at risk of serious illness, they can usually be treated at home with antibiotic medication.

The length of treatment will depend on whether the lower or upper part of your child’s urinary tract is infected. For lower UTIs, a three-day course of antibiotics is usually recommended. For upper UTIs, a 7 to 10-day course of antibiotics is usually recommended.

Your child may experience some side effects while taking antibiotics, but these are usually mild and should pass once they stop taking the medication. Common side effects of antibiotics include feeling sick, vomiting, an upset stomach, diarrhoea and a loss of appetite.

If necessary, paracetamol can also be used to treat any fever or discomfort your child has. However, non-steroidal anti-inflammatory drugs (NSAIDs) – such as ibuprofen – should not be used if your child has a UTI, as they can harm the kidneys. Aspirin should never be given to children under the age of 16.

If your child is unable to swallow tablets or capsules, they can be given antibiotics and paracetamol in liquid form.

Your child’s condition will usually improve within 24 to 48 hours of treatment. However, it is very important they finish the whole prescribed course of antibiotics to prevent the infection recurring.

Treatment in hospital

If your child is less than three months old, or it is thought that their condition could get worse, they will be referred to hospital for treatment.

Doctors may feel your child is at risk of becoming more seriously ill without hospital treatment if:

• they appear to be very unwell, dehydrated or unable to keep down oral medication because they keep vomiting
• they display unusual symptoms, such as reduced urine flow, high blood pressure (hypertension), or a noticeable lump or mass in their tummy (abdomen) or bladder
• they have been previously diagnosed with a condition that affects their urinary system

In these cases, your child will usually need to stay in hospital for a few days to receive antibiotics directly into a vein (intravenous antibiotics). As with cases treated at home, your child should improve within 24 to 48 hours.

Follow-up

Most UTIs in children will clear up within a day or two and won’t cause any long-term problems. Go back to your GP if your child is not showing any signs of improvement by this point.

In many cases, your child won’t need to be seen again once they have recovered. However, doctors may recommend carrying out some scans to check for any problems in your child’s urinary tract that could have contributed to the infection.

Situations where further tests may be recommended include when:

• your child is less than six months old
• there is no improvement in your child’s symptoms within 24 to 48 hours of treatment
• your child has any unusual symptoms, such as reduced urine flow, high blood pressure, or a noticeable lump or mass in their abdomen or bladder
• your child has repeated UTIs

Read our page on diagnosing UTIs in children for more information about the scans your child may have.