People with one kidney often have few or no health problems and normal life expectancy, according to the National Kidney Foundation. Most people can live with no kidneys, but to function they require dialysis, a treatment Himmelstein is undergoing.
A world of strangers reaches out
Himmelstein was diagnosed in 2012 with tuberous sclerosis complex, a genetic disorder that caused his kidneys to fail. He was placed on the deceased donor kidney transplant list that could mean a seven-year wait for a donation.
But within six months of creating his Facebook page, "New Kidney for Stu," Himmelstein was contacted by several strangers across the globe who offered to donate.
"When I started my Facebook page, I would get messages from someone in Quebec City, someone from Colorado, out of the blue," Himmelstein said. "You get those and it's like, there are walking angels among us."
A person must pass a few health screenings and have a compatible blood type. Himmelstein has type O blood -- the blood-type for a universal donor, but can only receive type O.
So far, none of Himmelstein's "angels" have been able to donate.
Himmelstein's plan to turn to Facebook isn't unique. In 2013, the National Center for Biotechnology Information released a study that described social media as a "powerful tool for increasing rates of live kidney donation."
Of the 91 patient cases researches reviewed, nine received kidney donations through Facebook, the study revealed.
Himmelstein was guided in creating his page by someone who had gone through the same struggle.
Jonathan Daniels, a Fort Lauderdale, Florida, antique shop owner, was put in touch with Himmelstein through a colleague in the medical field.
Daniels found a kidney on Facebook just three years ago.
"When I started on this journey, I basically felt like I was banging my head on the wall," Daniels said.
A success story in California
Daniels was diagnosed with Wegener's granulomatosis, a rare disease that caused kidney failure, loss of his hearing and limited use of his arms and legs. He was placed on a deceased donor list, but his family shared his story on Facebook and within three months, they found success.
A 38-year-old man in Los Angeles, California, saw Daniels' Facebook page and offered one of his kidneys. His grandmother had kidney failure when he was a boy, he told Daniels, and an altruistic donor saved his grandmother's life.
"He can only think that something went off in his mind because he said through the kindness of a stranger, he got his spitfire of a grandmother back," Daniels said.
The kidney transplant was a success, and Daniels' health quickly improved. He still visits doctors frequently, but his hearing, mobility and kidney function were restored.
Daniels offered to help Himmelstein reach the same goal.
"We've tapped into this sort of circle of kindness," Daniels said.
Himmelstein still practices medicine from his office despite a drop in his energy and a need for dialysis treatments. His patients are mostly elderly with chronic illnesses, including kidney failure.
"I think I've always been an empathetic physician, but in ways this makes me appreciate what the patient is going through even more," Himmelstein said. "I just want to continue doing what I love and helping people."
But Himmelstein's goal expands beyond finding a donor. Finding altruistic donors through social media could dramatically decrease the number of people waiting on transplants.
"On one hand we have a social media quest, on the other, we have this need to raise awareness about donations," Himmelstein said.
Added Daniels: "If you think about it, there's a reason we have two kidneys but only need one. God gave us a spare."