The kidneys are two bean-shaped organs found below the rib cage, one on each side of the spine. Each one is about the size of a fist. The kidneys filter excess waste, minerals and fluid from the blood by making urine.

People with end-stage kidney disease, also called end-stage renal disease, need to have waste removed from their bloodstreams. This can be done using a machine, which is called hemodialysis; a procedure to filter the blood called peritoneal dialysis or by having a kidney transplant.

A kidney transplant is usually the treatment of choice for kidney failure, compared with a lifetime on dialysis.

Kidneys from living donors tend to have fewer complications and last longer than those from deceased donors.

As more people wait for kidney transplants, living kidney donations have become more common. Since there aren't enough kidneys from deceased donors to meet the need, living-donor kidney transplants offer another option.

Types of live kidney donation

You may choose to donate your kidney in one of two ways:

• Directed donation, in which you name a specific transplant recipient. This is the most common type of living-donor organ donation.
• Nondirected donation, also known as good Samaritan or altruistic donation, in which you do not name the recipient of the donated organ. The match is based on medical need and compatibility.

If you and your intended recipient aren't compatible, paired-organ donations or donation chain programs can help make transplants possible.

• Paired-organ donation. Two or more organ-recipient pairs trade donors so that each person gets an organ that matches their blood type. A nondirected living donor also may participate in paired-organ donation to help match incompatible pairs.
• Donation chain. More than one pair of incompatible living donors and recipients may be linked with a nondirected living donor to form a donation chain for compatible organs. When this happens, multiple recipients can benefit from a single nondirected living donor.

A donor nephrectomy is an operation to take out a healthy kidney from a living donor for transplant into a person whose kidneys no longer work as they should.

A living-donor kidney transplant offers another way to receive a kidney instead of waiting for one from a deceased donor. A living donor can donate one of their two kidneys, and the remaining kidney is still able to meet the body's needs.

The first successful organ transplant in the U.S. took place in 1954 and used a living kidney donor. At the time, it required open surgery. Today, most kidney donation surgeries are done using minimally invasive laparoscopic techniques, sometimes with the use of robot-assisted technology.

The most common living-donor surgery is kidney donation. In the U.S., about 6,000 living kidney donations take place each year.

Donor nephrectomy comes with some risks. These may come from the surgery itself, from how well your remaining kidney works afterward, and from and the mental and emotional impact of donating an organ.

For people receiving a kidney, transplant surgery is often worth the small surgical risk because it is a potentially lifesaving procedure. For donors, however, kidney donation surgery involves the risk of and recovery from a procedure they don't need for their health.

Immediate, surgery-related risks of donor nephrectomy include:

• Pain.
• Infection.
• Hernia.
• Bleeding and blood clots.
• Wound complications and, in rare cases, death.

Living-donor kidney transplant is the most widely studied type of living organ donation, with more than 50 years of follow-up data. Studies show that people who have donated a kidney have a similar life expectancy to those who haven't donated.

Some studies show that living kidney donors may have a slightly higher risk of kidney failure compared with the general population. However, the risk of kidney failure after donor nephrectomy is still low.

Some long-term health risks of living kidney donation include high blood pressure and elevated protein levels in urine, a condition called proteinuria.

Donating a kidney or any other organ also may cause mental health issues, such as anxiety and depression. Donors may feel regret, anger, resentment or mental distress, particularly if the donated kidney fails.

Overall, most living organ donors are satisfied with their decision to donate.

Before you can donate a kidney, you'll undergo a thorough evaluation to ensure that you're eligible to donate and to reduce any risks from surgery.

Making an informed decision

Donating a kidney is a personal choice that deserves careful thought and consideration of both the risks and benefits. Talk through your decision with your friends, family and other people you trust.

You should not feel pressured to donate, and you may change your mind at any point.

In the U.S., living-donor transplant centers are required to provide an independent donor advocate to support the informed consent process. This advocate is often a social worker or counselor who can help you discuss your feelings and answer any questions you have.

General criteria for kidney donation include:

• Age 18 years or older.
• General good health.
• Two kidneys that work well.
• A willingness to donate.
• No history of high blood pressure, kidney disease, diabetes, certain cancers or major risk factors for heart disease.
• Completion of a thorough physical and psychological evaluation at the transplant center.

If you qualify to be a living donor, the transplant center is required to explain all aspects of organ donation and obtain your informed consent to the procedure.

Choosing a transplant center

If you're donating your kidney to a specific person, their care team may recommend a transplant center for your donor nephrectomy. If you're a nondirected donor, your healthcare professional may suggest a transplant center, or you can choose one yourself.

When considering a transplant center, you may want to:

• Learn about the number and type of transplants the center performs each year.
• Ask about the transplant center's organ donor and recipient survival rates.
• Compare transplant center statistics using the database maintained by the Scientific Registry of Transplant Recipients.
• See if the center is keeping up with the latest transplant technology and techniques. This usually means that the program is strong and growing.
• Look at additional services provided by the transplant center, such as support groups, travel arrangements and referrals to other resources.
• Find out if the transplant center participates in paired-organ donation or donation chain programs.