What is kidney failure?

The kidneys are two bean-shaped organs that lie on the left and right side of your spine, below your ribs and behind your belly. Each kidney is about the size of a fist: 4 or 5 inches long.

The kidneys' job is to filter your blood. They remove waste from the body, control your fluid balance, and maintain the correct levels of electrolytes. Each kidney has around a million tiny filters called nephrons to help with this. Even if 90% of your kidneys aren’t doing their job correctly, you might not notice any symptoms or problems.

However, if blood stops flowing into a kidney, part or all of it could die. That can lead to kidney failure.

When your kidneys lose the ability to effectively filter waste from your blood, kidney failure will occur. Some factors that can interfere with the health and function of your kidney include:

  • Exposure to toxins like environmental pollutants or certain medications
  • Trauma to your kidney
  • Certain acute and chronic diseases
  • Severe dehydration