Like countless others, this month I was admitted to the UCSF Medical Center for surgery. What makes me unusual is this: I’m healthy. This surgery was completely unnecessary. But at the end of it, I was short a vital organ.

Yup. I donated my kidney to someone I’ve never met.

* * *

Ten thousand people died each year because of the kidney shortage. Without a transplant, the five-year survival rates with kidney failure are about the same as brain cancer. Living donation bought the recipient on average 16 years of life with a working kidney.

I learned all these statistics in college, mostly because I’m a nerd with an interest in health policy (though at the time I wanted to be a soap opera writer). And to “get involved,” I briefly considered starting a group to promote organ donation. I thought a lot about how offering benefits to donors could end the shortage.

But I didn’t; I got into yoga instead. And even though it seems so obvious, I never really considered donating myself.

The day my path to donating really began, I was at a grocery store buying a clementine. It struck me then how lucky I was to be there, how much work others had done to provide me all the bounties of my privileged modern life. Later that day, I talked with a friend who was graduating college and wanted to do something important.

“Why not give your kidney?” I said, maybe jokingly. She took it seriously though, and for the first time I took it seriously, too. Why not? Why not be a hero and save someone’s life?

When I first told my parents, my dad laughed. I think he doubted that I’d go through with it. My mom was very quiet. The next time I called home, she ambushed me with a carefully compiled list of every possible risk associated with kidney donation, scary descriptions included. At first I was upset by this, but in retrospect I probably would have felt a lot worse if my mother was carefree about her only son going under the knife.

* * *

Of course, most living kidney donors donate to family members or friends.

But many people who need a kidney find it difficult or impossible to find a suitable donor. Because kidney disease and conditions that cause it (such as obesity and diabetes) run in families, the people who need a kidney transplant often can’t find one. Consequently, although kidney failure disproportionately burdens low-income Americans, it is high-income Americans who are most likely to find a living donor. Race matters, too. In 2013, African-Americans made up over a third of the kidney wait list but received less than a quarter of kidney transplants.

Dialysis, while it staves off death, leaves only 20 percent of people able to work; patients are exhausted and struggle to carry on their daily lives. Receiving a transplant doubles the life expectancy of someone on the waiting list and radically improves their quality of life.

Meanwhile, the donor faces few ramificationsDonating a kidney is extremely safe. The risk of death in surgery is about the same as the risk of death in childbirth for women over 35—about 1 in 3,000—and long-term health ramifications appear to arise in fewer than 1 percent of donors. Kidney donors, admittedly an unusually healthy group pre-surgery, live as long or longer than non-donors.

* * *

The day I got the call they had found a match for me, I knew I’d go through with my promise. On the phone, I became acutely aware of how superfluous my kidney was to my life, and how meaningful it would be for my recipient.

I was a little nervous the day of the surgery but everything went smoothly. And the actual recovery from surgery has been anticlimactic. The pain has been easily managed with pills, though I have been sleeping a bit more than normal. I was pretty scared to look at the incisions and turned away when nurses came to inspect them. But when I peeked, I was surprised to see how small they were.

A lot of people have asked if I worry that a family member will need a kidney and I won’t have a spare one. Given that my family doesn’t have a history of kidney disease, high blood pressure or diabetes, the chances of that are fairly remote (the average American only has a 3.26 percent chance of developing kidney failure in his or her lifetime).

Of course, I worry (but I also I have a ton of cousins). I do wish we had the Israeli policy of granting priority on the transplant wait list to family members of living donors, so that living donors don’t have to deal with that fear.

To me, it’s a small inconvenience to tackle a major issue of inequality that plagues the health care system.

White or wealthy patients are much more likely to receive transplants. Patients who can travel easily can be placed on multiple regional transplant wait lists, greatly increasing their chance of getting a transplant. That doesn’t sit right with me.

I’m not alone — the number of Americans donating to people they don’t know has tripled in the past dozen years, even as overall transplantation rates have stagnated.

And why not? I can do this one thing that will save someone’s life. In all likelihood, the main things it will leave me with are a tiny scar and a great story to tell my grandchildren. How many other chances will I get to do something so meaningful?