| Your
kidneys are bean-shaped organs, each about the size of your fist. They are located near
the middle of your back, just below the rib cage. The kidneys are sophisticated trash
collectors. Every day, your kidneys process about 200 quarts of waste products and extra
water. The waste and extra water become urine, which flows to your bladder through tubes
called ureters. Your bladder stores urine until you go to the bathroom.
The wastes in your blood come from the normal breakdown of active muscle and from the
food you eat. Your body uses the food for energy and self-repair. After your body has
taken what it needs from the food, waste is sent to the blood. If your kidneys did not
remove these wastes, the wastes would build up in the blood and damage your body.
what is "renal function"?
Your health care team may talk about the work your kidneys do as renal function. If you
have two healthy kidneys, you have 1 00 percent of your renal function. This is more renal
function that you really need. Some people are bom with only one kidney, and these people
are able to lead normal, healthy lives. Many people donated a kidney for transplantation
to a family member or friend. Small declines in renal function do not cause a problem. In
fact, you can be healthy with 50 percent of your renal function if it remains stable.
But many people with 50 percent of their renal function have a kidney disease that will
get worse. You will have some serious health problems is your have less than 20 percent of
your renal ftmction. If your renal function drops below 1 0 to 15 percent, you cannot live
long without some form of renal replacement therapy--either dialysis or transplantation.
why do kidneys fail?
Most kidney diseases attack the nephrons, causing them to lose their filtering
capacity. Damage to the nephrons may happen quickly, often as the result of injury or
poisoning. But most kidney diseases destroy the nephrons slowly and silently. It may take
years or even decades for the damage to become apparent.
The two most common causes of kidney disease are diabetes and high blood pressure. If
your family has a history of any kind of kidney problems, you may be at risk for kidney
disease.
diabetic nephropathy
Diabetes is a disease the keeps the body ftom using sugar as it should. If sugar stays in
your blood instead of breaking down, it can act like a poison. Damage to the nephrons from
unused sugar in the blood is called diabetic nephropathy. If you keep you blood sugar
levels down, you can delay or prevent diabetic nephropathy.
high blood pressure
High blood pressure can damage the small blood vessels in your kidneys. The damaged
vessels cannot filter poisons from your blood as they are supposed to.
Your doctor may prescribe blood pressure medication . A group of blood pressure
medicines called ACE inhibitors appears to give extra protection to the kidneys in
patients with diabetes.
inherited and congenital kidney diseases
Some kidney diseases result from hereditary factors. Polycystic kidney disease (PKD), for
example, is a genetic disorder in which many cysts grow in the kidneys. PKD cysts can
slowly replace much of the mass of the kidneys, reducing kidney Rmction and leading to
kidney failure.
other causes of kidney disease
Poisons and trauma, for example a direct and forceful blow to your kidneys, can lead to
kidney disease.
Some over-the-counter medicines can be poisonous to your kidneys if taken regularly
over a long period of time. Products that combine aspirin, acetaminophen, and other
medicines such as ibuprofen have been found to be the most dangerous to the kidneys.
If you take painkillers regularly, check with your doctor to make sure you are not
putting your kidneys at risk.
how do kidneys fail?
Many factors that influence the speed of kidney failure are not completely understood.
Researchers are still studying how protein in the diet and cholesterol levels in the blood
affect kidney function.
acute renal failure
Some kidney problems happen quickly, like an accident that injures the kidneys. Losing a
lot of blood can cause sudden kidney failure. Some drugs or poisons can make your kidneys
stop working. These sudden drops in kidney function are called acute renalfailure (ARF).
ARF may lead to permanent loss of kidney function. But if your kidneys are not
seriously damaged, acute renal failure may be reversed.
chronic renal failure
Most kidney problems, however, happen slowly. You may have "silent" kidney
disease for years. Gradual loss of kidney function is called chronic renalfailure or
chronic renal disease.
end-stage renal disease (esrd)
The condition of total or nearly total and permanent kidney failure is called end-stage
renal disease (ESRD). People with ESRD must undergo dialysis or transplantation to stay
alive.
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