Signs & Symptoms of Kidney Infection in Toddlers

Updated February 21, 2017

Most kidney infections (pyelonephritis) start as bladder infections, a common condition in toddlers and young children, according to Larissa Hirsch, MD of Bladder infections most often occur when bacteria enter the urethra (the tube that carries urine out of the bladder) and develop into an infection in the bladder. If prompt medical treatment -- usually antibiotics -- does not occur, the bacteria can move from the bladder to the kidneys and cause a kidney infection, a serious illness that can lead to permanent kidney damage. By recognising the signs and symptoms of kidney infection in a toddler, parents can ensure children will receive prompt medical treatment.

Frequent and/or Painful Urination

Toddlers experiencing any type of urinary tract infection (bladder or kidney) might complain of burning or irritation when urinating. You might also notice that your toilet-trained toddler experiences more frequent "accidents." While these symptoms in themselves usually indicate a simple bladder infection, they can also be present in a more severe kidney infection. If your toddler continues to experience these symptoms after being treated for a bladder infection and/or develops new symptoms, seek a doctor's opinion.


According to paediatrician Dr. William Sears, toddlers normally do not develop a high fever with a mild bladder infection, but do experience this symptom when suffering from a kidney infection. You might also notice chills or shaking accompanying the fever. During a kidney infection, expect the fever to stay high (102ยบ or higher) throughout the illness. Sears warns that, while most bladder infections do not turn into kidney infections, parents should take any signs of a kidney infection seriously and seek immediate medical treatment for children they suspect suffer from this illness.

Lower Back or Side Pain

A toddler might complain that his back hurts or his lower side (location of the kidneys) hurts. The pain will be persistent and will worsen over time. When you examine the toddler, you will not notice any bruising or signs of injury.


Paediatrician Dr. Alan Greene of suggests that toddlers and babies suffering from a kidney infection will experience nausea, vomiting and even diarrhoea. Young toddlers and infants might refuse to eat or drink and will often act irritable. You might also notice signs of jaundice (a yellowish cast to the skin) in very young toddlers and babies.

Abdominal Pain

During a kidney infection, a toddler might complain of a stomach-ache. Their abdomen might be tender to the touch. Pre-verbal toddlers will hold their stomachs or seem unwilling to play, eat or engage in other normal activities.

Pus or Blood in the Urine

You might notice this condition, known as hematuria, when changing your toddler's diaper. The hematuria might also be accompanied by a foul or strong smell to the urine.

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About the Author

A former children's librarian and teacher living in Dallas, Erin Carson loves to share her knowledge of both literature and parenting through her writing. Carson has a master's degree in library science and a bachelor's degree in English literature. As a freelance writer, Carson has published numerous articles on various websites.