In the U.S., an estimated 14 percent of the population has chronic kidney disease, and roughly 661,000 Americans have kidney failure. Of these, 468,000 people are on kidney dialysis, and almost 200,000 live with a functioning kidney transplant.

MedlinePlus and the National Institute of Diabetes and Digestive and Kidney Diseases have helpful information about how kidney transplants and other options can help.

What are kidneys?

Your kidneys are two bean-shaped organs that filter out waste and extra water, make hormones, and do other important things to keep you healthy. They are located on either side of your spine and are each about the size of your fist.

What causes kidney failure?

Diabetes and high blood pressure are the main causes of chronic kidney disease, which is the gradual loss of kidney function. Other conditions that affect the kidneys include autoimmune diseases like lupus and inherited diseases like polycystic kidney disease.

Some people live with kidney disease for years, others quickly progress to kidney failure. Kidney failure means that your kidneys have lost most of their ability to function–less than 15 percent of normal kidney function.

Medication and other methods of managing kidney disease help some people maintain kidney function for years. Others progress quickly to kidney failure.

Dialysis and kidney transplants are two treatments used to replace failing kidneys. Dialysis takes the place of your kidneys by helping remove waste and water from your blood, but doesn't fully replace everything your kidneys normally do.

Can a transplant help?

When your kidneys have failed, a transplant may also be a good option. Compared to dialysis, a working transplanted kidney does a better job of filtering waste, replacing your failed kidneys, and keeping you healthy.

However, a kidney transplant isn't for everyone. Anyone interested in a kidney transplant should be evaluated by a transplant center, as some people may not be healthy enough for transplant surgery.

While a transplant is a good treatment for kidney failure, it's not a cure. You need to take medicines daily so your body doesn't reject the new kidney. You also need to see your health care professional regularly.

Getting a transplant

Your health care professional will refer you to a transplant center for tests to see if you're healthy enough to receive a transplant. Living donors, such as family or friends, need to be tested to make sure they're healthy enough to donate a kidney.

If you have a living donor, don't worry about being a perfect "match." Today, innovations such as kidney exchanges allow transplant surgeons to get around incompatibilities and make many living donor transplants possible.

If you don't have a living donor, you'll be placed on a waiting list to receive a kidney. You'll have regular blood tests while you wait for a kidney. The center must have a recent sample of your blood to match with any kidney that becomes available. As soon as a kidney is available, you must go to the hospital to have your transplant. Donated organs need to be used in a specific amount of time or they may not be usable.

During surgery

Surgery usually takes three to four hours. The damaged kidneys are not usually removed.

If a family member or friend is donating the kidney, you'll schedule the surgery when it's best for you, your donor, and your surgeon. One surgeon will remove the kidney from the donor, while another prepares you to receive the donated kidney.

After surgery

Many people report feeling better right after having transplant surgery. For others, it takes a few days for the new kidney to start working.

You will probably need to stay in the hospital for several days to recover from surgery–longer if you have any problems. You'll have regular follow-up visits after leaving the hospital.

If you have a living donor, the donor will probably also stay in the hospital for a couple of days, although probably less time than you will.

Transplant rejection

Transplant rejection often begins before you feel any symptoms. Rejection occurs when the immune system attacks the "foreign" transplanted kidney.

The routine blood tests that you have at the transplant center will reveal early signs of rejection. You may develop high blood pressure or notice swelling because your kidney isn't getting rid of extra salt and fluid in your body.

If you think you may have transplant rejection, contact your health care professional immediately. Rejection can often be treated, but only if it is detected early. Your health care professional will treat early signs of rejection by adjusting your medicines to help keep your body from rejecting your new kidney. Rejection does not necessarily mean you will lose your transplant.

Additionally, when you're taking anti-rejection medicines, you're at a greater risk for infection.

Anti-rejection medicines can dull symptoms of problems such as infection. Call your transplant center right away if you aren't feeling well or have:

• a fever of more than 100 degrees
• drainage from your surgical scar
• burning when you pass urine
• a cold or cough that won't go away