Living kidney donation offers the best long-term outcomes for patients with end-stage renal disease, but the evaluation process for potential donors is intensely rigorous. The primary goal of this extensive, multi-stage screening is to ensure the complete and long-term safety of the donor. This assessment is designed to protect the donor from complications during surgery and throughout their remaining life with a single kidney. Many individuals who volunteer are disqualified, which is a protective measure guided by decades of medical data, not a reflection of their generosity.
Major Chronic Health Conditions
The presence of certain systemic diseases often results in immediate disqualification because they significantly increase the risk of the remaining kidney failing years after the donation. Severe hypertension, particularly if uncontrolled or requiring multiple medications, is a significant barrier. A pre-existing condition that stresses the renal system can accelerate the progression to the donor’s own kidney failure after donation.
Diabetes, both Type 1 and Type 2, is generally considered an absolute contraindication due to the established link between the disease and future kidney damage. The risk of developing kidney disease after donation is substantially higher for diabetic individuals. Some centers cautiously consider donors over age 60 with very well-controlled Type 2 diabetes, provided they show no signs of existing kidney or vascular damage.
A history of active or recent malignancy also typically excludes a person from donation, though highly curable, localized cancers may be exceptions. Disqualification occurs because the cancer could recur, or the donation process risks transmitting an undiagnosed micro-metastasis to the recipient. Significant cardiovascular disease, such as a history of a heart attack or severe coronary artery disease, is a disqualifier because major surgery presents an unacceptably high risk to the donor. Severe pulmonary or liver diseases that could complicate anesthesia or recovery will also prevent donation.
Infectious Disease Screening Requirements
Disqualification due to infectious diseases focuses on preventing transmission to the recipient, whose immune system is suppressed after transplantation. Human Immunodeficiency Virus (HIV) infection is a firm disqualifier in most centers due to the risk of transmitting the virus and causing severe complications in an immunosuppressed state. Active infection with Hepatitis B or Hepatitis C virus (HBV or HCV) also typically prohibits donation, as the transplanted organ could transmit the disease.
However, some programs allow a Hepatitis C-positive donor to give a kidney to a Hepatitis C-positive recipient, or a recipient who can be immediately treated with antiviral medication. Screening includes nucleic acid testing for these viruses to minimize the risk of “window period” transmission. Any active infection, such as severe sepsis or active tuberculosis, requires immediate deferral until the infection is completely cleared and the donor is fully recovered.
Kidney Function and Structural Health
The assessment of the donor’s existing kidney health is highly detailed, ensuring the remaining organ can sustain life without long-term complications. The Glomerular Filtration Rate (GFR) measures how effectively the kidneys filter waste. For acceptance, a donor must have a measured GFR well above the minimum threshold, often requiring a result of 90 milliliters per minute or higher. This high GFR ensures that even after the expected 25% to 40% functional decline following donation, the remaining kidney will function healthily. A GFR below 60 milliliters per minute is an absolute contraindication.
Proteinuria, the presence of excess protein in the urine, is a marker of existing kidney damage and is disqualifying if the amount exceeds 300 milligrams in a 24-hour collection. Structural issues are examined using imaging tests like CT scans and ultrasounds. A history of recurrent kidney stones or anatomical abnormalities like polycystic kidney disease will prevent donation because these conditions increase the risk of future complications in the single remaining kidney. A strong family history of early-onset kidney disease may also lead to disqualification, suggesting a genetic predisposition to kidney failure.
Lifestyle, Age, and Psychological Barriers
Factors beyond physical organ health also play a role in the disqualification process, focusing on minimizing surgical risk and ensuring the donor’s long-term welfare. Potential donors must be at least 18 years old to legally provide informed consent, though there is no strict upper age limit if the individual is otherwise healthy. Severe obesity, typically defined by a Body Mass Index (BMI) over 35, significantly increases the risk of surgical complications, such as wound infection and blood clots, and is a common reason for exclusion.
The psychological evaluation is equally important, ensuring the decision to donate is voluntary and fully understood. A donor will be disqualified if there is evidence of coercion, financial motivation, or an inability to comprehend the risks and consequences of the surgery. Untreated or severe mental health conditions, active substance use disorder, or a lack of commitment to necessary long-term follow-up care also serve as disqualifiers.