Transplant organs don't always last a lifetime—that's where retransplants come in

Transplanted organs can be rejected by the body immediately, months after transplant, or slowly over years

Organ rejection remains a huge challenge for organ transplant recipients. Rejection occurs when a recipient's immune system identifies a transplanted organ as foreign and attacks it. Recipient-donor screening processes try to match antigens to help reduce this risk.

Living donations most commonly involve a kidney or part of a liver

In 2023, more than 6,900 transplants were made possible thanks to living donors. Living donation is when a living person donates an organ or part of an organ—usually one of their two kidneys or part of the liver, since that organ can regenerate in a healthy person. Much more rarely, living donors donate other organs. Living donations often occur when someone wants to ensure a loved one has certainty that they will quickly receive a needed organ.

Donated hearts remain viable three times longer now with new tech

Advances in organ perfusion systems have significantly lengthened the amount of time donated hearts can remain viable for transplant, expanding the possibilities for donor organs to wider geographic areas. "Heart in a box" devices, developed in recent years, enable effective oxygen flow in the donor heart during transport, which means that hearts can now travel farther to potential recipients and still be in good condition.

In 2024, the US had more organ transplants than ever before—besting the 2023 record

More than 48,000 organ transplants were performed in 2024, and about 46,630 were performed in 2023. These record highs are illustrated here as part of data from 1988 to partway through 2025. Kidneys, livers, and the heart remain the most common transplanted organs. (Some users may encounter a paywall.)

The first successful organ transplant was performed in 1954

The successful kidney transplant procedure, at what's now-called Brigham and and Women's Hospital, ushered in a new medical era and gave hope to patients with organ failure. The recipient, 23-year-old Richard Herrick, lived eight more years after receiving the donated organ from his living twin brother, Ronald.

Organ transplants can come with a price tag of more than $2M without insurance

According to 2025 report data that was graphically represented by Statista, average costs for organ transplants can be as steep as $2.3M for a double lung transplant and $1.9M for a heart. These figures are based on what was actually charged to insurance companies—not what individual patients paid. Following the actual transplant there are also additional costs associated with the procedure, including lifelong immunosuppressant drugs.

Listen to why thousands of donated human kidneys are thrown away annually, even as thousands of people are awaiting a kidney transplant.

Immunosuppressants enable organ transplants, but come with severe side effects

This drug cocktail helps to lower your body's natural response to attack a transplanted organ. Such medications usually need to be taken for a lifetime after receiving an organ and can come with serious side effects including high blood pressure, diabetes, increased risk of some cancers, and high cholesterol, among others.

Organ donation isn't usually logistically possible if you die at home

Since organs need to be well-preserved for organ donation, with oxygen flowing through the body, internal organs often aren't viable for organ donation if someone dies at home. But some tissues—like eye corneas and skin tissue—may still be donated since they remain usable for a longer period without oxygen flow.

The global xenotransplantation market may already be valued at more than $13B.

3 US maps illustrate transplants, donors, and organ waitlist additions—by state.

How heart transplants work

Heart transplants require an old heart to be removed and a new one to be installed without killing the patient. How does that work? In this easy-to-understand five-minute video, learn each step of the intricate process, from donor matching to the preservative solution a heart is doused in while it is transported.

One man lived with a gene-edited pig kidney for 271 days, setting a record, before he received a human kidney.

Xenotransplants are an experimental last resort for the terminally ill when they cannot or will not receive a human organ.

Read why one man agreed to get a pig kidney in 2025 to replace his own failing organ

The 68-year-old New Hampshire man told USA Today that a motivator for the experimental surgery was his belief that he was going to die anyway, and other people suffering from kidney disease could gain valuable insights. Yet the surgery bought him time—he lived 271 days with a pig organ and later received a human kidney transplant. Clinical trials began in 2026 to test the pig xenotransplants in more people.

Research advances suggest death takes much longer than we realized

Recent research indicates that organs, including the brain, are better at handling a lack of oxygen after the heart stops beating than previously known. Such findings may open up possibilities that include someday reversing certain death processes and expanding the availability of organs available for organ donations. (Some users may experience a paywall.)

Cells can last in the human body from days to a person's entire life

Despite claims that a person's body replaces itself every seven to 10 years, the rate at which cells die and are replaced varies by cell type. Gastrointestinal cells that line the digestive tract and stomach last only a few days, while some heart muscle cells and most neurons are around from birth until death.

A clinical trial is underway in 2026 to help kidney transplant recipients avoid a lifetime of immunosuppressing drugs

This later-stage clinical trial, in Chicago and Taiwan, evaluates the efficacy and safety of a new cellular therapy that may be swapped in for immunosuppressing drugs among kidney transplant recipients. The study randomizes people to either receive standard immunosuppressants or this cellular therapy and fewer immunosuppressants. It only includes kidney transplant recipients receiving organs from live donors so transplant surgery timing won't hinge on the unpredictable schedule of performing surgery and follow-up care when a donor dies.

NSF-funded research into matching algorithms improved the success of organ transplants

Investigations in game theory, including concepts focused on creating mutually beneficial partnerships—matching theory—led to the design of computer systems that efficiently matched kidney recipients and live donors, resulting in higher-quality matches. By 2019, these matching algorithms were used for multi-organ exchanges.

If surgeons removed organs, including one of your lungs, a kidney, your spleen, appendix, tonsils, part of your liver, and even some of your reproductive organs, you could still survive.

Which organs can you live without?

While there are some organs (such as the heart) that people simply can’t live without, there are other organs that can be removed without a huge impact. Patients who have their appendix removed, for example, experience no changes to their daily...

Artificial intelligence may improve organ donation systems—and even organ health

Mayo Clinic transplant experts suggest that artificial intelligence could potentially improve organ donation systems in several ways, including better identifying patients most at risk for organ rejection, enhancing donor-recipient matching, and helping to avoid organ transplant needs by identifying health issues earlier.

White patients waited 374 days for a kidney—Black patients waited 727 days

A 2022 congressionally mandated report highlighted racial inequities in the US organ transplant system, including disparities that made it more likely white people will be placed on organ wait lists than Black people. It spotlighted inequities such as racial differences in median kidney wait times identified in earlier research. The report, from the National Academies of Sciences, Engineering, and Medicine, recommended fixes including that the Department of Health and Human Services develop national performance goals for the system and achieve equity in the system in the next five years.

As of 2025, perfect synthetic replication of natural organs remains elusive

Advancements such as 3D printing muscles, performing vaginal reconstruction with colon tissue, and growing organs in a lab have shown promise, but artificial options and transplanting substitutions continue to exhibit functional and performance limitations compared to their natural equivalents.

You can sign up to donate your organs at this website

A single person who chooses to donate their organs upon death can provide organs for as many as eight people. You can sign up to become an organ donor or update your donation status information at this website, or you can typically sign up at your state's Department of Motor Vehicles. Many states allow individuals to declare which tissues and organs you consent to donate (i.e. organs, eyes, and skin tissue). It's recommended to discuss your decision with your family so they are aware of your wishes.

Brain death is a top source of organ donation

Brain death is a significant source of organ donations—approximately 40% of organs in the US and the UK are recovered from people who experience brain death. Patients declared brain dead and hooked up to intensive care unit machines will still have oxygen flowing to organs like the heart, lungs, and kidneys—preserving those organs.

Several years after the English law changed, organ donation rates haven't improved

A 2024 analysis found that several years after England changed its organ donation system to an opt-out donation system there was no improvement to the country's organ donation rates, perhaps highlighting the need for better understanding and education around the law.

'Donation after circulatory death' is on the rise

This occurs when a patient in a coma is on life support and family members agree to donate the organs. Watch this video about a 2025 New York Times investigation that identified 12 instances across nine states of bungled or premature attempts to retrieve organs from people whose families had authorized withdrawal of life support.

Explore different pig-to-human xenotransplantation possibilities, including using pig pancreatic cells for treating diabetes.

Organoids: 3D organs grown from stem cells in the lab

An organoid is a three-dimensional construct composed of multiple cell types that originate from stem cells that can simulate the architecture and functionality of native organs. One big benefit of these lab-grown organs is that drug candidates can be tested in model systems without needing live patients.

Brain death is a top source of organ donation

Brain death is a significant source of organ donations because patients declared brain dead and hooked up to intensive care unit machines will still have oxygen flowing to organs like the heart, lungs, and kidneys—preserving those organs.

Cross-species transplantation has been attempted in medicine for more than 300 years.

In 1984, a dying infant lived for three weeks with a baboon heart inside her chest.

Scientists may have discovered why gene-edited pig kidneys are rejected in humans

In November 2025, researchers studying how a brain-dead donor’s body responded to the transplantation of a genetically engineered pig kidney, published that they’ve identified immune system reactions that may explain why these pig organs get rejected. What’s more, they were able to reverse the rejections with an already available drug combination and the kidney functioned well. They also pinpointed a way to detect a potential rejection up to five days sooner.

UNOS oversees the entire US organ donation system

The United Network for Organ Sharing is a private, nonprofit organization that manages much of the US organ donation and transplantation system under a federal contract. Medical urgency, blood type, organ size, and geography of the donor and recipient are all factors determining how someone who needs an organ is matched with someone who donated an organ.

Chinese scientists transplanted a pig lung into a human being in 2025—but it had to be removed.

See how pig heart valves have been placed in humans since 1965.

Pig-to-human transplant work has raised concerns about donor pigs' living conditions.

Pig organ transplants are apparently kosher—you just can’t eat them

Science writer Mary Roach speaks with journalist Terry Gross about her latest book, “Replaceable You: Adventures in Human Anatomy” and discusses topics including why pig organs have become of such interest and what religious leaders have told her about pig organs and compliance with Jewish dietary law.

Watch this video letter (via Facebook) from a kidney recipient to his donor

A kidney recipient named Justin reads a letter he wrote to his deceased donor about how the person's generous kidney donation saved his parents from having to watch him suffer and his brother from having the pressure of perhaps being his only shot at a life-saving transplant.

England changed to an organ donation opt-out system in May 2020

A law that went into effect in May 2020 in England changed the country's organ donation regulations, reflecting public support for organ donation. Now, adults are typically presumed to have agreed to donate their own organs upon death unless they declare they're refusing to donate organs (or their family opts them out).

Without the option of modern blood transfusions, some doctors in the mid-1800s tried to help save cholera patients by injecting them with cow's milk, hoping it would boost their nutrition and hydration.

In the US, you must actively sign up to donate your organs

The US has an opt-in donation system for organ donation—meaning people must provide consent to proceed with any donation. Locations including Spain, the United Kingdom, and Argentina have an opt-out donation system, which means individuals are presumed to be donors unless they actively refuse consent.

New blood cells are created by hematopoietic stem cells

Blood is made up of several cells with various functions and short lifespans, so the body must have a constant supply of replacements. These replacements are created by hematopoietic stem cells, rare cells that live in bone marrow and can regenerate themselves and blood cells.

A first-of-its-kind clinical trial taps livers from gene-edited pigs to clean blood

The experimental dialysis-like treatment from United Therapeutics, eGenesis, and OrganOx, is designed to help people with liver failure. The therapy, which involves attaching the modified pig liver externally, filters a patient’s blood so their own livers can temporarily rest and perhaps heal.

You can sign up to donate your body to science

It's a separate process to donate your body for medical research; you usually must contact a whole-body donation program directly. Bodies can be donated for medical research, for forensic analysis research, or for medical students to work with as they learn anatomy and surgery, among other purposes. Learn more about numerous accredited organizations that provide human bodies, organs, and tissues to medical researchers and students.

A Nobel laureate discuss whether stem cells can extend lifespan

Listen to Nobel laureate Shinya Yamanaka discuss the potential of induced pluripotent stem cells to extend human lifespan. By reprogramming adult cells into embryonic-like stem cells, scientists might be able to rejuvenate tissues and treat age-related diseases—though ethical and safety concerns remain.

An interactive explanation of blood transfusion

The antigens and Rh factors of blood cells (which determines your blood type) must be compatible with your immune system—which is why blood transfusions between patients must have matching types. In a mismatch, the immune system will attack and destroy donor blood cells, triggering a potentially fatal reaction.

Environment and genetics explain why animals have widely different lifespans

Both environmental conditions and genetic factors shape how long various animals live. For some creatures, colder conditions allow for less energy use and slower aging. Larger animals have fewer predators. While humans don't live the longest, we are a rare species that successfully lengthened its average lifespan over time.

Bone marrow transplants were the first successful type of stem cell therapies

Bone marrow contains two types of stem cells: Skeletal (develop into bone, cartilage, and more) and hematopoietic, which create new blood cells. The latter are critical in bone marrow transplants, and give the recipient the ability to create healthy blood cells to fight diseases like leukemia.