Question: May one donate a kidney to a friend who suffers from kidney failure such that it poses a danger to his life?
Answer: Before we begin the actual discussion, we must start off by saying that the actual operation one must undergo in order to donate a kidney to someone else is not all that dangerous for the donor, for with the great developments in modern medicine throughout the past few decades, almost ninety-nine percent of kidney donors return to good health and full function.
Now, let us begin discussing the matter at hand. The Poskim disagree whether or not one may place one’s self into a situation of doubtful danger in order to save a friend who is in certain danger. For instance, if one sees another being swept into the sea and knows that this individual will certainly drown because he does not know how to swim whereas he, the onlooker, knows how to swim well, however, with the sea in such an agitated and surging state, it is possible that the onlooker will drown as well. In such a situation, the Poskim disagree whether or not one is permitted to put himself in harm’s way in order to save the individual from certain death.
Halachically speaking, most Poskim agree that one may not put himself in a situation of doubtful danger in order to save another from certain danger. The great Radbaz rules likewise and adds that one who does so is considered a “pious fool” because this is acting contrary to Halacha.
Based on this, several great Poskim of the previous generation, including Hagaon Harav Yitzchak Yaakov Weiss zt”l, Hagaon Harav Eliezer Yehuda Waldenberg zt”l, and others, write that one may not donate a kidney to another since the actual operation to have the kidney removed involves some medical risks (i.e. doubtful danger) and one may not place one’s self in a situation of doubtful danger in order to save another from certain danger.
Nevertheless, after delving deeply into this matter, Maran Rabbeinu Ovadia Yosef zt”l points out that the above disagreement among the Poskim regarding whether or not one may place himself in harm’s way in order to save a friend from certain danger applies only when there is substantial probability or significant percentages of danger. However, with the vast developments in the medical field in recent years whereby the percentage of danger has been drastically reduced to nearly insignificant figures, this can no longer be classified as even a “doubtful danger”. Based on this, even according to the above Poskim who forbade this, nowadays, Halacha dictates that this would indeed be permissible. Maran zt”l proceeds to support his view from the words of the Radbaz who writes that when the Rambam writes (Chapter 1 of Hilchot Rotze’ach) that anyone who is able to save the life of a fellow Jew and does not transgresses the prohibition of “You shall not stand [idly by] on your fellow’s blood”, this applies even when there is “minimal danger” to the onlooker, such as when one sees another drowning in the sea or being attacked by bandits or a wild animal, which all pose a slight danger to the onlooker and nevertheless, he is obligated to jump in and save the person in danger. Thus, the Radbaz himself teaches us that when the risk of danger is only slight such that it is not an “equal doubt” (i.e. 50-50), one may enter a possibly precarious situation in order to save another from certain danger.
Thus, halachically speaking, Maran zt”l rules (in his Responsa Yabia Omer, Volume 9, Choshen Mishpat, Chapter 12) that it is permissible and even a Mitzvah to donate a kidney to save another Jew who is in terminal danger due to kidney disease or failure. The merit of this Mitzvah shall surely protect the donor from all harm one-thousand-fold. However, one must make sure to only undergo the operation at the hand of expert surgeons and one who observes the Mitzvot shall know no evil.
May Hashem send His word and heal all of the ill members of the Jewish nation, as the verse states, “Peace peace to him that is far and to him that is near, said Hashem, and I will heal him.”