A kidney transplant is a surgical procedure that replaces a diseased kidney with a healthy one from a compatible donor. It is recommended for people with advanced kidney disease to restore kidney function and improve quality of life.

Also called a renal transplant, this surgery is performed when the kidneys are severely damaged and can no longer filter waste or maintain the body’s balance of water and minerals.

A nephrologist must recommend the procedure, and full recovery usually takes about three months. During this time, it is important to take all prescribed medications and follow a balanced diet under the supervision of a nutritionist.

Doctor speaking with hospitalized patient

When it is indicated

A kidney transplant is recommended for advanced chronic kidney disease caused by:

Chronic inflammation of the glomeruli (glomerulonephritis)
Pyelonephritis
Polycystic kidney disease
Kidney tumor
Chronic or acute ischemia, which reduces blood flow to the kidneys
Reflux nephropathy, IgA nephropathy, or sickle cell nephropathy
Urinary tract obstruction (obstructive uropathy), which may affect one or both kidneys
Congenital kidney malformations
Progressive kidney damage from poorly controlled high blood pressure or diabetes
Conditions such as hemolytic-uremic syndrome, Goodpasture syndrome, or Alport syndrome

Advanced chronic kidney disease occurs when kidney damage persists for more than three months, leading to the loss of the kidneys’ ability to filter blood and remove waste from the body.

A kidney transplant is indicated when the damage is irreversible, meaning kidney function cannot be restored, or when the person requires multiple hemodialysis sessions each week.

It is important to schedule an appointment with a nephrologist to assess kidney health and determine if a transplant is needed.

How to prepare for the transplant

Preparation for a kidney transplant begins long before surgery and includes a complete medical evaluation to identify any conditions that could prevent the procedure or increase the risk of organ rejection.

Before the surgery, the doctor evaluates the compatibility of the donor kidney, which can come from a living or deceased donor who is healthy and free of disease. The donor may or may not be related to the recipient.

To evaluate the recipient’s health and kidney function, the doctor may order a physical exam, blood tests, and imaging studies such as a CT scan or MRI.

How compatibility is assessed

Compatibility between the donor and recipient is determined through blood tests and human leukocyte antigen (HLA) typing.

Donors may be related or unrelated to the recipient, as long as the compatibility tests confirm a match.

How the transplant is performed

A kidney transplant is performed by a nephrologist under general anesthesia in a hospital accredited to perform transplants.

The surgery follows these steps:

Administer general anesthesia.
Make an incision in the abdomen to insert the donor kidney.
Connect the donor kidney’s arteries and veins to the recipient’s blood vessels.
Attach the donor ureter to the bladder.
Close the incision and apply a sterile dressing.

The recipient’s nonfunctional kidney is usually left in place, as it may still have some useful function, especially in the early recovery period before the transplanted kidney is fully functional.

A diseased kidney is only removed if it is causing complications such as infection.

Recovery process

Recovery after a kidney transplant generally starts with a hospital stay of about one week, during which the surgical, anesthetic, and nursing teams closely monitor for any signs of transplant reaction or complications.

The transplanted kidney usually begins working soon after surgery, but in some cases, it may take a few days. When function is delayed, hemodialysis may be needed until the new kidney begins to work properly.

The surgical dressing will be changed by the nurse as necessary, and if the person experiences pain, the doctor may prescribe pain medication. Once the patient is stable, shows no signs of rejection, and has normal test results, the doctor can authorize discharge, with continued treatment and follow-up at home.

Post-transplant care

Some care measures your doctor may advise after the kidney transplant include:

1. Daily care

After hospital discharge, some daily precautions are important to ensure proper recovery and prevent complications:

Take immunosuppressant medications such as prednisone, azathioprine, and cyclosporine at the prescribed times to prevent organ rejection.
Take prescribed antibiotics to prevent possible infections.
Avoid physical activity during the first three months.
Undergo weekly checkups during the first month, then every two weeks until the third month due to the risk of rejection.
Avoid smoking.
Avoid contact with sick people and polluted environments.

Full recovery typically takes around three months. After this period, the doctor may recommend physical activities such as walking or swimming under professional guidance to maintain a healthy weight and prevent complications such as high blood pressure or high cholesterol.

2. Dietary care

A post-transplant diet should be guided by a nutritionist and strictly followed until blood test results are stable. The following recommendations usually apply:

Eat at least five servings of fruits and vegetables per day.
Consume high-fiber foods, such as cereals and seeds.
Increase intake of calcium- and phosphorus-rich foods like skim milk, almonds, and salmon, or take supplements prescribed to maintain strong bones and teeth.
Avoid sodium, found in table salt and processed or frozen foods, to help control fluid retention, swelling, and high blood pressure.
Eat lean meats like chicken or fish in the portions recommended by the nutritionist.
Limit sugar intake and avoid sweets to prevent blood sugar spikes. Prefer complex carbohydrates such as rice, corn, bread, pasta, and potatoes.
Avoid greasy and fried foods.
Avoid alcoholic beverages, as they can affect liver function.
Limit potassium-rich foods such as bananas and oranges, since some medications can increase potassium levels.
Avoid eating raw vegetables; cook them and disinfect with 20 drops of sodium hypochlorite per two liters of water for 10 minutes.
Avoid seafood, raw eggs, and processed meats.
Store food in the refrigerator for up to 24 hours and avoid frozen leftovers.
Wash fruits thoroughly and prefer cooked or baked options.
Stay hydrated by drinking the amount of fluids recommended by the doctor or nutritionist.

Following a balanced and varied diet helps maintain a healthy weight, supports overall organ function, and reduces the risk of transplant rejection, infections, and complications such as cardiovascular disease, diabetes, or high blood pressure.

Possible risks and complications

The main risks and complications after a kidney transplant include:

Rejection of the transplanted kidney
Surgical wound infection
Urinary tract or systemic infections
Blood clots or thrombosis
Urinary obstruction
Bleeding or hemorrhage

Although rare, complications from general anesthesia may also occur, such as allergic reactions, nausea, vomiting, low blood pressure, chills, fever, or infection.

Immunosuppressive medications can cause side effects such as weight gain, osteoporosis, diabetes, swelling, skin or mucosal changes (like acne or mouth ulcers), increased risk of skin cancer or lymphoma, and excessive hair growth, especially in women.

Warning signs to seek medical help

Contact a nephrologist or go to the nearest emergency department if you develop symptoms such as fever above 100.4°F (38°C), painful urination, swelling, sudden weight gain, diarrhea, frequent coughing, or shortness of breath.

You should also seek medical attention if the surgical site becomes swollen, warm, or red, as this may indicate an infection.

Kidney transplant rejection

Transplant rejection can occur minutes or hours after surgery, known as hyperacute rejection. It is characterized by fever and a lack of urine output and, though rare, must be treated immediately with surgery to remove the transplanted kidney.

Rejection can also occur within weeks or months (acute rejection) or develop gradually over several years (chronic rejection), slowly impairing kidney function.

Rejection is typically detected through blood tests showing elevated creatinine or imaging exams. To confirm rejection, the doctor may order a kidney biopsy to examine the tissue under a microscope.

Symptoms of transplant rejection

The main symptoms of kidney transplant rejection include:

Fever
Tenderness or pain near the transplant site
Swelling in the feet, ankles, hands, or throughout the body
Rapid weight gain
High blood pressure
Reduced urine output
Extreme fatigue
Body aches
Headache
Chills
Nausea or vomiting
Diarrhea

These symptoms should be reported to the doctor immediately for evaluation and treatment.

Contraindications

A kidney transplant may be contraindicated for people with metastatic cancer, severe heart or lung disease that prevents surgery, or untreated active infections.

It may also not be recommended for individuals with active substance use or untreated psychiatric conditions.

Each case should be evaluated individually by the doctor to assess potential risks and benefits.

Kidney Transplant: When It's Indicated, How It's Performed & Care