“It is much harder to do the right thing every day when no one is looking. Donating a kidney is much easier.” Susan Hou only says that because she really believes that is true.

Seven-and-a-half years ago, Dr. Hou, a nephrologist at the University Medical Centre, Chicago, gave her kidney to her patient. “I've had patients ask me for a kidney, but the woman I finally gave it to never asked me. My only criterion was that I should give it to someone smaller than me, and that really narrows it down,” the rather petite nephrologist with a cracking sense of humour says. “The question is not why I did it, but what took me so long. There was much reluctance to use unrelated donors in the U.S. then,” Dr. Hou explains in a chat after a lecture on renal disorders in pregnancy organised by Tanker Foundation on Monday. The strongest criticism came from India, where people said women without rights would be forced to donate one of their kidneys to their husband. Now there are drugs to make unrelated transplants work too.

The process of evaluating a donor's intent and physical condition is crucial, she adds. There can be a lot of coercion; people are not so convinced that they should be donating. “When I donated, nobody was pressuring me. If you believe in the brotherhood of man, then there are no unrelated donors.”

One has to ensure that there is no money changing hands. “If we have the feeling a donor doesn't really want to donate, then we tell them they cannot do it.” The donor also has to be healthy enough and with good kidney function that will likely be good in future. It is essential that the donor has no infection or cancer that he could give to the recipient.

She herself had a “not-so bad” recovery from her traditional nephrectomy. But that is Dr. Hou as usual underplaying the drama. Twelve days after surgery, she flew to Philadelphia for a lecture and 13 days later, she was on a flight to Budapest. None of her children was surprised she had donated her kidney to a patient, and “Mark [Molitch, her husband, an endocrinologist] was very happy later, but very worried…on the day before the surgery.”

When colleagues ask her if she recommends every nephrologist donate a kidney to a patient, she says matter-of-factly, “You don't have to do it unless you want to. You can do something else.” “Everyone pats you on the back and gives you a plaque when you donate a kidney, but they don't do that when you hold the elevator door open or refuse a drug company,” Dr. Hou says. On Monday, Georgi Abraham, founder-trustee of Tanker Foundation, honoured her, and yes, a plaque was in the picture.

But, yes, you can see it really does warm the cockles of her heart that her patient is still running on the donated kidney. “I am happy every year that the kidney's still working… Seven-and-a-half years later, someone doesn't need dialysis or a new kidney, it's a great feeling,” Dr. Hou says.