Acute kidney injury

Kidney injury: See main article: Kidney injury

Acute: An acute condition is newly arising, sudden, rather than long-lasting or recurring ("chronic"). Doesn't always mean severe although it often is. See: Acute, Acute Disorders

Kidney injury: See main article: Kidney injury

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Sudden loss of renal function, as manifested by decreased urine production, and a rise in serum creatinine or blood urea nitrogen concentration (azotemia). [from HPO]

Source: GTR (NCBI/NIH)1

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Acute kidney injury (AKI) is sudden damage to the kidneys that causes them to not work properly. It can range from minor loss of kidney function to complete kidney failure.

AKI normally happens as a complication of another serious illness. It's not the result of a physical blow to the kidneys, as the name might suggest.

This type of kidney damage is usually seen in older people who are unwell with other conditions and the kidneys are also affected. Read more about who's at risk of AKI.

Source: NHS Choices UK2

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Acute kidney injury: Sudden loss of renal function, as manifested by decreased urine production, and a rise in serum creatinine or blood urea nitrogen concentration (azotemia).

Acute renal failure is usually classified into prerenal (response to severe volume depletion), intrinsic (response to acute cytotoxic, ischemic, or inflammatory insults) and postrenal (response to obstruction of the passage of urine) etiologies.3

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Acute kidney injury adverse event: A kidney disorder adverse event that results in the rapid loss or decline of kidney function4

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Acute Kidney Injury: Abrupt reduction in kidney function. Acute kidney injury encompasses the entire spectrum of the syndrome including acute kidney failure; Acute Kidney Tubular Necrosis; and other less severe conditions.5

Symptoms of Acute kidney injury

When hemolytic uremic syndrome causes acute kidney injury, a child may have the following signs and symptoms:

  • edema—swelling, most often in the legs, feet, or ankles and less often in the hands or face
  • albuminuria—when a child's urine has high levels of albumin, the main protein in the blood
  • decreased urine output
  • hypoalbuminemia—when a child's blood has low levels of albumin
  • blood in the urine

Source: NIDDK (NIH)6

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Symptoms of acute kidney injury

In the early stages of AKI, there may not be any symptoms. The only possible warning sign may be that the person isn't producing much urine, although this isn't always the case.

However, someone with AKI can deteriorate quickly and suddenly experience any of the following:

Even if it doesn't progress to complete kidney failure, AKI needs to be taken seriously. It has an effect on the whole body, changes how some drugs are handled by the body and could make some existing illnesses more serious.

Source: NHS Choices UK7

Causes of Acute kidney injury

Causes of acute kidney injury

Most cases of AKI are caused by reduced blood flow to the kidneys, usually in someone who is already unwell with another health condition.

This reduced blood flow could be caused by:

AKI can also be caused by a problem with the kidney itself, such as glomerulonephritis. This may be caused by a reaction to some drugs, infections or contrast medium (the liquid dye used in some types of X-rays).

It may also be due to a blockage affecting the drainage of the kidneys, such as:

Source: NHS Choices UK8

Specific Causes of Acute kidney injury

Hemolytic uremic syndrome: When the kidneys and glomeruli—the tiny units within the kidneys where blood is filtered—become clogged with the damaged red blood cells, they are unable to do their jobs. If the kidneys stop functioning, a child can develop acute kidney injury—the sudden and temporary loss of kidney function. Hemolytic uremic syndrome is the most common cause of acute kidney injury in children.

Source: NIDDK (NIH)9

Differential Diagnosis for Acute kidney injury

Chronic kidney disease: AKI is different to chronic kidney disease, where the kidneys gradually lose function over a long period of time.

Source: NHS Choices UK10

Treatments for Acute kidney injury

Treating Acute Kidney Injury

If necessary, a health care provider will treat acute kidney injury with dialysis—the process of filtering wastes and extra fluid from the body with an artificial kidney. The two forms of dialysis are hemodialysis and peritoneal dialysis. Most children with acute kidney injury need dialysis for a short time only.

Source: NIDDK (NIH)11

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Treating acute kidney injury

Treatment of AKI depends on the underlying cause and extent of illness. In most cases, treating the underlying problem will cure the AKI.

GPs may be able to manage mild cases in people who aren't already in hospital. They may:

  • advise stopping any medication that may be causing the situation, or making it worse - it may be safe to resume some of these when the problem is sorted
  • treat any underlying infections
  • advise on fluid intake to prevent dehydration (which could cause or worsen AKI)
  • take blood tests to monitor levels of creatinine and salt - to check how well a person is recovering
  • refer to a urologist (genitourinary surgeon) or nephrologist (kidney specialist) if the cause isn't clear or if a more serious cause is suspected

Admission to hospital is necessary in cases where:

  • there's an underlying cause that needs urgent treatment - such as a urinary blockage, or if the person is seriously unwell; most people need hospital care to treat the underlying cause, allowing the AKI to get better
  • there's a risk of urinary blockage - because of prostate disease, for example
  • the person's condition has deteriorated , and regular blood and urine tests are needed to monitor how well their kidneys are working
  • the person has a complication of AKI

Source: NHS Choices UK12

Preventions for Acute kidney injury

Preventing acute kidney injury

Those at risk of AKI should be monitored with regular blood tests if they become unwell or start new medication. It's also useful to check how much urine you're passing.

Any warning signs of AKI, such as vomiting or producing little urine, require immediate investigation for AKI and treatment. People who are dehydrated, or at risk of dehydration, may need to be given fluids via a drip.

Any medicine that seems to be making the problem worse, or directly damaging the kidneys needs to be stopped, at least temporarily.

The National Institute for Health and Care Excellence (NICE) has produced detailed guidelines on preventing, detecting and managing AKI.

Read the NICE guidelines here.

Source: NHS Choices UK13

Names and Terminology for Acute kidney injury


Acute renal failure

Source: GTR (NCBI/NIH)14

Synonyms and Related Terms

Synonyms of Acute kidney injury:



Category of Acute kidney injury:


Related Symptoms

Read more information about these related symptoms:

Related Diseases and Conditions

Read more information about these diseases and medical conditions related to Acute kidney injury:

Symptom Articles

Read more about these related symptoms:

Disease Articles

Read more about these related conditions and diseases:

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  1. Source: GTR (NCBI/NIH): gtr/ conditions/ CN001736/ 
  2. Source: NHS Choices UK: conditions/ acute-kidney-injury/ 
  3. Source: Human Phenotype Ontology
  4. Source: OAE Ontology
  5. Source: MeSH (U.S. National Library of Medicine)
  6. Source: NIDDK (NIH): health-information/ kidney-disease/ children/ hemolytic-uremic-syndrome
  7. Source: NHS Choices UK: conditions/ acute-kidney-injury/ 
  8. ibid.
  9. Source: NIDDK (NIH): health-information/ kidney-disease/ children/ hemolytic-uremic-syndrome
  10. Source: NHS Choices UK: conditions/ acute-kidney-injury/ 
  11. Source: NIDDK (NIH): health-information/ kidney-disease/ children/ hemolytic-uremic-syndrome
  12. Source: NHS Choices UK: conditions/ acute-kidney-injury/ 
  13. ibid.
  14. Source: GTR (NCBI/NIH): gtr/ conditions/ CN001736/ 
  15. Source: Human Phenotype Ontology
  16. ibid.
  17. [from HPO]
  18. Source: GTR (NCBI/NIH): gtr/ conditions/ C0027080/ 
  19. Source: GHR (NLM/NIH): condition/ atypical-hemolytic-uremic-syndrome
  20. Source: CDC NNDSS: nndss/ conditions/ hemolytic-uremic-syndrome-post-diarrheal/ case-definition/ 1996/ 
  21. [from HPO]
  22. Source: GTR (NCBI/NIH): gtr/ conditions/ CN003192/ 

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Note: This site is for informational purposes only and is not medical advice. See your doctor or other qualified medical professional for all your medical needs.