Home » Urinary tract infection (uvi) in children and babies - symptoms and treatment

Urinary tract infection (uvi) in children and babies - symptoms and treatment

Mother sits with a feverish child in her lap

Urinary tract infections (often called uvi) are common in infants and also quite common in older children. Urinary tract infections with fever, or renal pelvic inflammation, can become dangerous and needs to be treated quickly with antibiotics. Urinary tract infections without fever, catarrh or cystitis, are very unpleasant but not dangerous. Antibiotics also help there.

Urinary tract infections in infants and young children 

Urinary tract infections are quite common in children under one year, and especially common in boys. Most children under the age of two who get a urinary tract infection suffer a high fever (over 38.5 degrees) without any other symptoms. So the urine does not smell bad, they have not taken care of the genitals and they often (but not always) eat well. The only thing that makes us suspect that they have urinary tract infection is that they have a fever without any other symptoms.

Read more about fever in children in this post. 

Infants may also have urinary tract infections without fever, which can be diagnosed if they are not eating, or are not gaining weight. Then it is always good to take a urine sample.


In case of suspected urinary tract infection in young children, a urine test is needed. Pads and bags unfortunately can give rise to tainted specimens, where one can diagnose a urinary tract infection by mistake, so peeing in a mug is necessary. You simply have to sit with the baby in the lap and fit with a mug until they pee.

If the urine test of the specimen shows signs of urinary tract infection, it needs to be treated. In babies, you do this by sticking a syringe through the stomach and sucking up urine through the bladder. It is quick but hurts a little. The advantage is that you completely eliminate the risk of diagnosing a urinary tract infection when there is none. This risk is always present in the urine test because the urine may have caught bacteria on the way out through the genitals.

Urinary tract infection in older children 

In children over two years, there are three types of urinary tract infections: cystitis, pyelonephritis and asymptomatic bacteriuria (ABU). In smaller children, they do not differ, partly because they cannot discuss their symptoms, and partly because each is treated the same.

Bladder infection or cystitis

A cystitis, or lower urinary tract infection, is a urinary tract infection that irritates the bladder but has not risen to the kidneys. It is painful for the child but not as dangerous as a high urinary tract infection involving the kidneys.

The symptoms of a cystitis are burning or pain when the baby is peeing, that the baby needs to urinate often. The child has no fever. Leave a urine sample that is sent for cultivation. Antibiotics help.

Blood in the urine

Fresh red blood in the urine of children is almost always a sign of urinary tract infection. Dark blood in the urine, Coca-Cola-colored urine, is a sign of kidney disease. Seek medical attention at the medical centre for examination.

Kidney infection

Pyelonephritis, or renal pelvic inflammation, is a urinary tract infection where the bacteria grow in the kidneys. It is also seen in children over two years of age as a fever without other symptoms. Sometimes the children complain of stomach or back pain, sometimes it hurts to pee, sometimes the urine smells bad. Sometimes the children vomit. Usually not.

Renal pelvic inflammation in children needs to be treated with antibiotics and should be followed up with examination of the urinary tract later.

Asymptomatic bacteriuria

Asymptomatic bacteriuria means bacteria in the urine without symptoms. That's not true. These girls (it is most common in girls) have smelly urine. Really smelly urine. They urinate frequently. But it does not burn when urinating.

Previously, girls with asymptomatic bacteriuria were treated aggressively by the health care system. They were given bactericidal agents directly into the bladder (terribly painful, repentant doctors and former patients) say time and time again. Thankfully, some wise researchers investigated if it helped and found that it didn't.

Unfortunately, antibiotics don't help either. Or, it removes the smell as long as you take it, but the smell and the bacteria come back. Also, antibiotics do not protect against pyelonephritis in children with ABU. On the contrary, the child has a bacterial strain in the bladder that the child manages to keep away from the kidneys. If you remove that bacterium with antibiotics, there is a risk that the next bacterium that creeps up through the urethra is a more aggressive bacterium that the child cannot manage to keep away from the kidneys.

Antibiotics for children with ABU do more harm than good!

Children with asymptomatic bacteriuria need to see a urotherapist or pediatric nurse who is an expert on urinating problems. She needs to check if the children empty the bladder when they are urinating, if they have overactive bladder or (usually) urinate infrequently and have an overcrowded bladder. Children need to be helped to pee regularly (every three hours). It can help but unfortunately it doesn't always.

Read more about peeing and good urinating habits here. 

Treat constipation!

Children over two years old with cystitis, pyelonephritis or ABU often have constipation. It should be treated, be sure to get good treatment for constipation if your child does not have soft plentiful stools without any problems every day, if your child has had urinary tract infection or ABU. The constipation means that there is a bowel stretched by the stool in the path of the bladder. This makes bladder control and bladder discharge more difficult, which in turn increases the risk of urinary tract infections.

Read more about constipation in children here. 

Read more:

Fever in babies and children - what to do and when is the fever too high?

Wetting themselves - treatment of bed wetting and daily incontinence in children

Constipation in children - symptoms and what helps against constipation

Nice and clever potty training that works

You can find all posts about childhood diseases here

11 thoughts on “Urinvägsinfektion (uvi) hos barn och bebis – symtom och behandling”

  1. Great information!
    My daughter got urinary tract infection at the age of 3 months, which was discovered by her having a 39 degree fever. We went to the hospital where we found out that she had a urinary tract infection.
    After treatment with 2 different antibiotics when the bacteria initially spread, she became healthy after a month. After that, a number of different hospital visits came to find that nothing had gone up in the kidneys, so-called renal pelvic inflammation. So she had to do a variety of ultrasounds and urine tests and other things and the whole summer went on until everything was ready and we were told that she was completely healthy and nothing went up in the kidneys.

    I was really funny when this happened when it is my first child and I had never heard of this before, but luckily everything went well and she had no inflammation and everything disappeared after the antibiotic treatment.

    But after that I can promise that I am ALWAYS observant of high fever or smelly urine in my daughter when it may come back, have I heard if you got it once?
    When I think the urine smells strong or strange, I leave a urine sample at the health center, rather than too much at all ... then you get an answer immediately and do not have to worry when treatment is urgently needed if it is a urinary tract infection.

    Today my daughter is 15 months old and has not received urinary tract infection since then, so nice!
    Pleasant summer!

  2. Hi Cecilia,
    Interesting reading, especially about asymptomatic bacteriuria. We have a son, 6 years old, who after being diaper-free and snoring dry for about a year suddenly began to pee when he was 4 years old. Every day, often several times a day. Sometimes everything in the bladder, sometimes a little grand. This has been going on for two years, with better and worse periods. Periodically, the kiss smells very bad, periodically not different at all.
    During these two years we have searched for urinary tract infection at the health center without the test showing bacteria, he has done ultrasound to see if the bladder empties (it did) and we have also been on bup to talk about this but we did not experience that they had the skills to handle this but talked about being afraid of the toilet, which he is not. We have also tried to pee on schedule (1-1.5 hours between toa visits) but it does not help either but he can still pee on you in between.
    Could it be that he has an undetected and untreated asymptomatic bacteriuria? Should we look further? If so, what should we say when we contact healthcare? This is a big concern for us, as it takes a lot of energy to handle this both mentally and practically with all clothes during different activities, plus he gets teased for "smelling fish".

    1. Hey! I definitely think you should look for it further. Make sure you get referral to pediatricians in the first place. Depending on where you live, there is a reception at the children's hospital or out "on the town", but the health care doctor knows. At the pediatrician, there are usually pediatric nurses with special knowledge in peeing and kissing problems, and you should also meet one of these. At best you can meet a pediatric urotherapist, but pediatric therapists are rare birds, unfortunately, so it is not possible to do so. What to say? Yes, what you have written here. And grumble on to the right skills! Talk to your friends with children and hear if there is any pediatrician or pediatrician who is good at kissing problems nearby. That's a common problem!

  3. All that, you will not remember such things on the straight arm the day you stand there with a child with uvi, but then you know where you have read about it and come back and look up this post and read it again 🙂
    I came up with another thing that I myself now know, but which surely many new parents can benefit from.
    In retrospect, I understand that it happens at least once in each and every family ... The little life learns to roll over on the stomach without telling anyone and then he or she has fallen to the floor. We were very scared and went to the emergency room for a check-up. (Now it was iofs Clara who fell to the floor, she is a Dandy Walker child, had it been Matilde we would probably have taken a deep breath and thought after a little first). In any case, we learned that if the child screams directly, does not lose consciousness and does not vomit, you do not have to rush away to the hospital neck over head ...

  4. Hi and thanks for a good blog with consistently nice tone and good and useful information. This time I think you put a lot of responsibility on the parent. I do not know how it worked in the county council where you work but it sounds like you do not trust the primary care but want to make the parent an expert over the district doctor. Very boring if it worked so badly! In my world, it is important that every parent has confidence in his or her district physician and that he / she has higher competence than I do when I bring my child. My hope / suggestion is well because your county council has well functioning and updated pm for how these diseases should be treated and which ones to be referred, so that these routines are available to the district doctor. Better to inform the district doctors than the parents in my opinion. The parent should be allowed to be a parent and only that, not a medical expert.
    Mvh Lina, doctor (in primary care) and mother of three children, one of whom received the wrong treatment (when visiting a medical center in another county) in pyelonephritis. (Incidentally, I also distinguish between the above four types of urinary tract infection - on both children and adults)

    1. Hey!

      I'll think about whether I can rephrase the post. But it is unfortunately based on repeated experience of improperly treated uvi in children of primary care physicians. Unfortunately. Unfortunately. I know that there are many super-child-competent district doctors (<3 er!) But unfortunately there is also the opposite.

      Cecilia

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