Your Kidneys and How They Work
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.
Diabetes is a disease that keeps the body
from 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 your 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
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 function and leading to kidney
Some kidney problems may show up when a
child is still developing in the womb. Examples include autosomal recessive
PKD, a rare form of PKD, and other developmental problems that interfere with
the normal formation of the nephrons. The signs of kidney disease in children
vary. A child may grow unusually slowly, may vomit often, or may have back or
side pain. Some kidney diseases may be "silent" for months or even
If your child has a kidney disease, your
child's doctor should find it during a regular checkup. Be sure your child sees
a doctor regularly. The first sign of a kidney problem may be high blood
pressure, a low number of red blood cells (anemia), or blood or protein in the
child's urine. If the doctor finds any of these problems, further tests may be
necessary, including additional blood and urine tests or radiology studies. In
some cases, the doctor may need to perform a biopsy -- removing a piece of the
kidney for inspection under a microscope.
Some hereditary kidney diseases may not be
detected until adulthood. The most common form of PKD was once called
"adult PKD" because the symptoms of high blood pressure and renal
failure usually do not occur until patients are in their twenties or thirties.
But with advances in diagnostic imaging technology, doctors have found cysts in
children and adolescents before any symptoms appear.
Other Causes of Kidney
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.