Acute kidney injury (AKI) is a sudden episode of kidney failure or kidney damage that happens within a few hours or a few days. AKI causes a build-up of waste products in your blood and makes it hard for your kidneys to keep the right balance of fluid in your body. AKI can also affect other organs such as the brain, heart, and lungs. Acute kidney injury is common in patients who are in the hospital, in intensive care units, and especially in older adults.
AKI can be caused by different factors:
Decreased blood flow. Some diseases and conditions can slow blood flow to your kidneys and cause AKI.
These diseases and conditions include:
- Low blood pressure (called “hypotension”) or shock
- Blood or fluid loss (such as bleeding, severe diarrhea)
- Heart attack, heart failure, and other conditions leading to decreased heart function
- Organ failure (e.g., heart, liver)
- Overuse of pain medicines called “NSAIDs”, which are used to reduce swelling or relieve pain from headaches, colds, flu, and other ailments. Examples include ibuprofen, ketoprofen, and naproxen.
- Severe allergic reactions
- Major surgery
Direct damage to the kidneys
Some disease and conditions can damage your kidneys and lead to AKI. Some examples include:
- A type of severe, life-threatening infection called “sepsis”
- A type of cancer called “multiple myeloma”
- A rare condition that causes inflammation and scarring to your blood vessels, making them stiff, weak, and narrow (called “vasculitis”)
- An allergic reaction to certain types of drugs (called “interstitial nephritis”)
- A group of diseases (called “scleroderma”) that affect the connective tissue that supports your internal organs
- Conditions that cause inflammation or damage to the kidney tubules, to the small blood vessels in the kidneys, or to the filtering units in the kidneys (such as “tubular necrosis,” “glomerulonephritis, “vasculitis” or “thrombotic microangiopathy”).
Blockage of the urinary tract
In some people, conditions or diseases can block the passage of urine out of the body and can lead to AKI. Blockage can be caused by:
- Bladder, prostate, or cervical cancer
- Enlarged prostate
- Problems with the nervous system that affect the bladder and urination
- Kidney stones
- Blood clots in the urinary tract