An organ transplant is a surgery that removes a healthy organ from one person (the donor) and places it into someone whose organ has failed or is failing (the recipient). It’s one of the most complex procedures in modern medicine, and it can be the only option when an organ stops working well enough to keep someone alive. In the United States alone, more than 100,000 people are on transplant waiting lists at any given time.
Which Organs and Tissues Can Be Transplanted
The list is longer than most people expect. Eight vital organs can be transplanted from a deceased donor: kidneys (both), liver, lungs (both), heart, pancreas, and intestines. Hands and faces can also be transplanted, though these are rare and technically demanding procedures involving bone, muscle, nerves, skin, and blood vessels all at once.
Beyond whole organs, tissue banks can store and distribute corneas, skin, heart valves, bone, veins, cartilage, tendons, and ligaments. Blood stem cells, collected from bone marrow, umbilical cord blood, or circulating blood, are transplanted to treat blood cancers and other diseases.
Living donors can give more than you might think. The most common living donation is a single kidney, but donors can also give a portion of their liver, one lobe of a lung, or parts of the pancreas and intestine. Because the liver regenerates, both the donor’s remaining portion and the transplanted segment can grow back toward full size. Living donors can even contribute skin (after cosmetic surgeries like a tummy tuck), bone (after knee or hip replacements), and blood products.
How Donors and Recipients Are Matched
Transplanting an organ from one person into another only works if the two bodies are biologically compatible. The matching process focuses on a few key factors. First, blood type has to be compatible, just like a blood transfusion. Second, doctors compare proteins on the surface of cells called human leukocyte antigens, or HLA. Everyone inherits a unique combination of these proteins, and the closer the match between donor and recipient, the lower the risk that the recipient’s immune system will attack the new organ. Three sets of these proteins matter most in kidney transplantation, and the fewer mismatches across those three, the better the long-term outcome.
Before surgery, a crossmatch test checks whether the recipient already has antibodies that would immediately attack the donor organ. If those antibodies are present, the transplant typically can’t proceed because the risk of instant rejection is too high. This entire matching process is coordinated nationally through an organ allocation network that connects transplant centers across the country.
How Organs Are Allocated on the Waiting List
Getting on a transplant waiting list doesn’t mean you’re in a simple first-come, first-served line. Each organ type uses a different scoring system to determine who receives the next available organ. For livers, the system uses a score called MELD 3.0 (updated in 2023) that measures how sick the patient is right now. Higher scores mean greater medical urgency, and those patients get priority, even if someone with a lower score might have better long-term survival after the transplant. The goal is to save the people most likely to die without one.
Hearts use a six-tier system based on what kind of medical support the patient currently needs. Someone on a temporary mechanical heart pump is in a higher tier than someone stable on medication alone. Lungs use a separate allocation score, and kidneys combine measures of donor organ quality with the recipient’s estimated survival after transplant. Geography also plays a role: organs are offered first to compatible recipients closer to the donor hospital because organs have limited preservation time outside the body.
What Happens During the Surgery
The process begins well before the operating room. Once a donor organ becomes available, a specialized surgical team recovers it, preserves it in a special container, and transports it to the recipient’s hospital. For deceased donors, this recovery is a formal, respectful procedure. For living donors, the removal and transplant surgeries typically happen at the same time in the same hospital.
The transplant surgery itself is complex and can take several hours depending on the organ. In a kidney transplant, the new kidney is usually placed in the lower abdomen rather than where the original kidneys sit. A heart transplant requires the recipient to be placed on a heart-lung bypass machine while the diseased heart is removed and replaced. Liver transplants involve disconnecting and reconnecting multiple blood vessels and bile ducts. Each organ has its own surgical challenges, but the core principle is the same: connect the new organ’s blood supply and verify it’s functioning before closing.
How the Body Can Reject a New Organ
The immune system treats a transplanted organ as foreign tissue and will try to destroy it unless suppressed with medication. Rejection comes in three forms, each on a different timeline.
Hyperacute rejection happens within minutes. It occurs when the recipient already has antibodies against the donor organ, triggering immediate blood clotting inside the new organ’s vessels. This leads to rapid organ death. Modern crossmatch testing has made hyperacute rejection rare, but it’s the reason that pre-transplant blood work is so critical.
Acute rejection develops between one week and several months after surgery. The immune system’s T cells and B cells recognize the foreign tissue and mount an attack. This is the type of rejection transplant teams monitor most closely in the early post-operative period, and it can often be treated by adjusting medications.
Chronic rejection unfolds over months to years and is now the leading cause of transplant failure. It involves a slow, ongoing immune response that gradually damages the organ. Chronic rejection is harder to reverse and is a major reason why transplanted organs don’t last forever.
Recovery and Hospital Stay
Recovery varies by organ, but the general arc is similar. After a liver transplant, for example, you can expect to spend 7 to 14 days in the hospital. The first few days are in intensive care for close monitoring. You’ll feel sore and need strong painkillers initially. Within a day or two, staff will help you sit up and start walking, which is important for preventing complications like blood clots.
You’ll only be discharged once three things are true: you’re physically strong enough to move around safely, your anti-rejection medication levels are stable, and you’ve learned enough about your condition to manage your care at home. After discharge, most patients return to the transplant clinic weekly at first, with visits gradually spacing out as recovery progresses. Full return to normal activities, including work, typically takes a few months, though this depends on the organ and any complications.
Life on Anti-Rejection Medication
Every transplant recipient takes immune-suppressing drugs for the rest of their life, or for as long as the transplanted organ is functioning. These medications prevent the immune system from attacking the new organ, but because they dial down immune activity broadly, they come with significant side effects.
The most commonly used drugs belong to a class that blocks a key immune signaling pathway. These are effective at preventing rejection, but they can damage the kidneys over time (responsible for over 70% of kidney failure cases after liver transplants) and cause nerve-related problems in 10% to 32% of patients, ranging from tremors and headaches to more serious symptoms like seizures or confusion. They also raise the risk of high blood pressure, diabetes, and high cholesterol.
Steroids, another standard component of the drug regimen, worsen metabolic problems by increasing insulin resistance and blood pressure. Metabolic syndrome, a cluster of obesity, high blood sugar, high blood pressure, and abnormal cholesterol, affects 44% to 58% of liver transplant recipients across various studies. Suppressing the immune system also reduces the body’s ability to fight infections and catch early-stage cancers, which is why transplant recipients need regular screenings and checkups for the rest of their lives.
Survival Rates and Costs
Modern transplant outcomes are remarkably good in the first year. National one-year patient survival rates sit at about 97% for kidney transplants, 94% for liver transplants, and 92% for heart transplants. Graft survival (whether the transplanted organ itself is still working) tracks slightly lower: roughly 95% for kidneys, 92% for livers, and 92% for hearts at one year. These numbers drop over five and ten years, largely due to chronic rejection and the cumulative toll of anti-rejection medications, but transplantation still offers dramatically longer and better-quality life than the alternative for people with organ failure.
The financial side is substantial. A kidney transplant averaged $442,500 in total cost as of 2020, with the surgery and hospital admission accounting for about 34% of that total. Immunosuppressive medications and related drugs made up roughly 7% of costs in the first six months. Insurance, including Medicare (which covers kidney transplants for eligible patients), handles most of these expenses, but out-of-pocket costs for medications and follow-up care can still be a long-term financial burden.