Having chronic and end-stage renal or kidney disease means that for some time your kidneys have not been working the way they should. Your kidneys have the important job of filtering your blood. They remove waste products and extra fluid and flush them from your body as urine. When your kidneys don't work right, wastes build up in your blood and make you sick.

Chronic kidney disease may seem to have come on suddenly. But it has been happening bit by bit for many years as a result of damage to your kidneys. Each of your kidneys has about a million tiny filters, called nephrons. If nephrons are damaged, they stop working. For a while, healthy nephrons can take on the extra work. But if the damage continues, more and more nephrons shut down. After a certain point, the nephrons that are left cannot filter your blood well enough to keep you healthy.

One way to measure how well your kidneys are working is to figure out your glomerular filtration rate (GFR). The GFR is usually calculated using results from your blood creatinine (say "kree-AT-uh-neen") test. Then the stage of kidney disease is figured out using the GFR. There are five stages of kidney disease, from kidney damage with normal GFR to kidney failure.

There are things you can do to slow or stop the damage to your kidneys. Taking medicines and making some lifestyle changes can help you manage your disease and feel better.

Chronic kidney disease is also called chronic renal failure or chronic renal insufficiency.

Chronic kidney disease is caused by damage to the kidneys. The most common causes of this damage are:

  • High blood pressure.
  • High blood sugar (diabetes).

Other things that can lead to chronic kidney disease include:

  • Kidney diseases and infections, such as polycystic kidney disease, pyelonephritis, and glomerulonephritis, or a kidney problem you were born with.
  • A narrowed or blocked renal artery. The renal artery carries blood to the kidneys.
  • Long-term use of medicines that can damage the kidneys. Examples include non-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen (Advil) and celecoxib (Celebrex).

You may start to have symptoms only a few months after your kidneys begin to fail. But most people don't have symptoms early on. In fact, many don't have symptoms for as long as 30 years or more. This is called the "silent" phase of the disease.

How well your kidneys work is called kidney function. As your kidney function gets worse, you may:

  • Urinate less than normal.
  • Have swelling from fluid buildup in your tissues. This is called edema (ih-DEE-muh).
  • Feel very tired or sleepy.
  • Not feel hungry, or you may lose weight without trying.
  • Often feel sick to your stomach (nauseated) or vomit.
  • Have trouble sleeping.
  • Have headaches or trouble thinking clearly.