The kidneys are two organs located in your midsection on either side of your spine in the middle of your back, just above the waist. They clean your blood, keep the balance of salt and minerals in your blood, and help control blood pressure.
When your kidneys are damaged, waste products and fluid can build up in your body, causing swelling in your ankles, vomiting, weakness, poor sleep, and shortness of breath. If you don't treat them, diseased kidneys may eventually stop working completely. Loss of kidney function is a serious -- and potentially fatal -- condition.
Your kidneys help filter waste, excess fluid, and toxins from your blood. They are also important for blood cell production and bone health. If kidneys don't work properly, harmful substances build up in the body, blood pressure can rise, and too much fluid can collect in the body's tissues, which leads to swelling, called edema.
If your kidneys fail, you will need dialysis or a kidney transplant to take over their job.
Marathon runners and other athletes who don't drink enough fluids while competing in long-distance endurance events may get acute renal failure because of a sudden breakdown of muscle tissue. This releases a large amount of protein into the bloodstream called myoglobin that can damage the kidneys.
What Causes Chronic Kidney Disease?
Kidneys that don't work well for longer than 3 months is called chronic kidney disease (CKD). It's dangerous, because you may not have any symptoms until a lot of damage, that often can't be repaired, has happened.