The kidneys are two organs located in your abdominal cavity 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 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 suffer acute renal failure due to a sudden breakdown of muscle tissue. This muscle breakdown releases a large amount of protein into the bloodstream called myoglobin that can damage the kidneys.
What Causes Chronic Kidney Disease?
Kidney damage and decreased function that lasts longer than 3 months is called chronic kidney disease (CKD). Chronic kidney disease is particularly dangerous, because you may not have any symptoms until considerable, often irreparable, kidney damage has occurred. Diabetes (types 1 and 2) and high blood pressure are the most common causes of CKD. Other causes are:
Inflammation in the tiny filters (glomeruli) within the kidneys; this can happen after strep infection and other conditions of unknown cause.
Polycystic kidney disease, in which fluid-filled cysts form in the kidneys over time. This is the most common form of inherited kidney disease.
Congenital defects, present at birth, are often the result of a urinary tract obstruction or malformation that affects the kidneys; one of the most common involves a valve-like mechanism between the bladder and urethra. These defects, sometimes found while a baby is still in the womb, can often be surgically repaired by an urologist.
Drugs and toxins, including long-term exposure to some medications and chemicals, such as NSAIDs (nonsteroidal anti-inflammatory drugs), like ibuprofen and naproxen, and use of intravenous “street” drugs