Acute Kidney Injury Symptoms & Causes

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Contact the Division of Nephrology

When your child is diagnosed with acute kidney injury you may have a lot of questions:

  • What exactly is acute kidney injury?
  • What are the treatments?
  • How will it affect my child long term?

We’ve tried to provide some answers to those questions here, and when you meet with our experts, we can fully explain your child’s condition and treatment options.

Background on the kidney

The kidney has three main functions:

  • Cleaning the blood – removing waste, toxins and extra fluid and maintaining the proper balance of chemicals and minerals
  • Regulating vitamins and minerals that help bone growth and development
  • Releasing hormones and vitamins that:
  1. Regulate the level of red blood cells produced by the body
  2. Help control blood pressure
  3. Regulate the amount of the body's nutrients including calcium and potassium

Out of these functions, it’s the sudden inability to clean the blood that presents the biggest complication of AKI. If the blood isn’t being cleaned and filtered, harmful toxins may build up in the bloodstream and cause significant damage.

What’s the difference between AKI and chronic kidney disease (CKD)?

Although AKI and CKD each result in a loss of kidney function, they differ in causes, symptoms, progression and treatment approaches.





Infection, medication exposure, surgery, trauma

About half of all pediatric cases are the result of kidney or bladder abnormalities that are present at birth



Very sudden onset, usually over hours or days

CKD is often detected when a pediatrician notices protein in the urine during a routine test



Kidneys fail rapidly


Kidney failure could take days, months or years


Treatment approaches

Targeted to the underlying cause of the kidney failure

Based on how well the kidneys are functioning and strongly focused on relieving symptoms


Read more about chronic kidney disease.


What causes AKI?

AKI is often caused by a sudden decrease in blood and/or oxygen flow to your child’s kidneys. This could follow:

  • An accident
  • Surgery
  • A condition that obstructs blood flow, like cardiac arrest

AKI may also occur if your child:

  • Takes certain medications that may be toxic to the kidneys
  • Injures her abdomen or back, like a bike-riding accident that results in a fall over the handlebars, or a skiing accident
  • Develops a sudden obstruction or blockage in her urinary tract, such as a kidney stone, that prevents urine from leaving her body
  • Contracts an infection such as hemolytic uremic syndrome (HUS), usually caused by the E. coli bacteria. The infection results in the blockage of the structures and blood vessels in the kidney
  • Is born with blood vessel abnormalities that cut off blood flow to her kidneys
  • Has another disease or condition that damages the kidneys, such as glomerulonephritis or lupus



What are the symptoms of acute kidney injury?

Symptoms of AKI come on suddenly, over the course of hours or days. They depend on the underlying cause, but some of the most common symptoms include:

  • Hemorrhage (heavy bleeding)
  • Fever
  • Rash
  • Bloody diarrhea
  • Severe vomiting
  • Abdominal pain
  • No urine output or high urine output
  • Pale skin
  • Edema (swelling of the tissues)
  • Swelling around the eye
  • Detectable abdominal mass

If your child has these symptoms, she may be especially at risk of AKI if she has or has had any of the following:

  • History of recent infection
  • History of dehydration
  • History of recent surgery
  • History of taking certain medications
  • History of trauma
  • Exposure to heavy metals or toxic solvents


Q: Is my child’s condition serious?

A: AKI is a serious condition, but it's usually reversible, and kidney function can be restored once we determine—and fix—whatever is causing the problem.

Q: Will my child’s kidneys recover completely?

A: This depends on the extent of the injury. If there has been significant injury, some kidney function may be permanently lost. If, for example, your child is left with 80 percent kidney function after an episode of AKI, it will still have to do still the work of a fully functioning kidney. Working harder means the kidney is more at risk for the normal wear and tear that affects everyone’s kidneys. Even so, remember that many people live a healthy life with only one kidney.

Q: How long will my child be hospitalized?

A: This depends on the cause of your child’s AKI, how sick she is, and how she responds to treatment. We'll make sure that she is comfortable and keep you informed of her progress at all times.

Q: When will my child’s kidneys regain their functioning?

A: The length of time it takes to recover from an episode of AKI depends on many factors, including the cause, severity, how long it lasted and how much damage was done to the kidneys.

Q: What’s the long-term outlook for my child?

A: Most children with acute kidney injury get better. After an episode of AKI, your child should consider kidney care to be a permanent part of her health care routine. She should see her doctor and have her blood pressure checked and urine tested every year to make sure that her kidney function has not deteriorated. Her doctor may also recommend that she’s followed by a nephrologist (a doctor who specializes in kidneys).

In some severe episodes of AKI, particularly if your child has another disease or condition, the kidneys may not gain back normal functionality, and your child may be a candidate for long-term dialysis and/or kidney transplant.


Questions to ask your doctor

There’s a lot of information to gather when your child is diagnosed with acute kidney injury. Here are some questions to get you started:

  • What caused my child’s AKI?
  • What’s the best treatment for her right now?
  • How much experience does this institution have in treating children with AKI?
  • What do I need to do now?

"Helping Your Child With Medical Experiences: A Practical Parent Guide"

Download our free booklet, “Helping Your Child with Medical Experiences: A Practical Parent Guide”. (Please note that Adobe Acrobat is required) and read about topics including:

  • Talking to your child about his condition
  • Preparing for surgery and hospitalization
  • Supporting siblings
  • Taking care of yourself during your child’s illness
  • Adjusting to life after treatment








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