Acute Renal Failure - What Happens

What Happens

Acute renal failure occurs within hours to days when the kidneys lose their ability to remove waste products and excess fluids from the body. The most common cause of this is reduced blood flow to the kidneys, either from dehydration, surgery, a severe infection, or injury. When blood flow to the kidneys decreases, waste products and excess fluids are not adequately removed from the body.

Treatment can usually reverse acute renal failure in a few days or weeks. But in some people it causes permanent kidney damage that leads to chronic kidney disease. A small percentage of them will need to have regular dialysis or a kidney transplant.

If acute renal failure is not treated, complications can develop that affect the entire body. These may include:

• Infection. This is one of the most common complications, because the body's immune system may stop working properly.
• Uremic syndrome (uremia). It can cause severe nausea, confusion, seizures, irregular heart rhythm, and fluid in the lungs (pulmonary edema).
• Increased potassium in the blood (hyperkalemia). This can lead to dangerous heart problems.

About half of people who develop acute renal failure recover, and most of those who recover have enough kidney function to live normal lives. Older adults and people who have other serious medical problems are less likely to regain their health. Those who die usually die from the problem that caused their kidney failure, not from the kidney failure itself.