The kidneys are two organs located on either side of your spine in the middle of your back, just above the waist. They perform several life-sustaining roles: They cleanse your blood by removing waste and excess fluid, maintain the balance of salt and minerals in your blood, and help regulate blood pressure.
When the kidneys become damaged, waste products and fluid can build up in the body, causing swelling in your ankles, vomiting, weakness, poor sleep, and shortness of breath. If left untreated, diseased kidneys may eventually stop functioning 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 a life-saving treatment called dialysis to take over their job.
Healthy kidneys handle several specific roles. Healthy kidneys:
Maintain a balance of water and concentration of minerals, such as sodium, potassium, and phosphorus, in your blood
Remove waste by-products from the blood after digestion, muscle activity, and exposure to chemicals or medications
Produce renin, an enzyme that helps regulate blood pressure
Produce erythropoietin, which stimulates red blood cell production
Produce an active form of vitamin D, needed for bone health
What Causes Acute Kidney Injury?
The sudden loss of kidney function is called acute kidney injury, also known as acute renal failure (ARF). ARF can occur following:
A traumatic injury with blood loss
The sudden reduction of blood flow to the kidneys
Damage to the kidneys from shock during a severe infection called sepsis
Obstruction of urine flow, such as with an enlarged prostate
Damage from certain drugs or toxins
Pregnancy complications, such as eclampsia and pre-eclampsia, or related HELLP Syndrome
Marathon runners and other athletes who don't drink enough fluids while competing in long-distance endurance events may suffer acute renal failure due to a sudden breakdown of muscle tissue. This muscle breakdown releases a chemical called myoglobin that can damage the kidneys.