Selena Gomez recently sat down to recount the story of her kidney transplant last summer, which she got after complications from her Lupus diagnosis. In an interview with NBC's "TODAY," the star sat down with best friend Francia Raisa, who graciously donated her kidney to Gomez. 

New details from Gomez reveal the process was much more difficult than she first admitted.

“I had arthritis. My kidneys were shutting down. My mentality was just to keep going,” Gomez said.

photo: Giphy

That's when the 25-year-old knew a transplant was necessary, but very hard to come by. "She goes, ‘I don't know what to do. The list is seven-to-10-years long,’” said actress Raisa. "I was like, ‘Of course I'll get tested.'"

Though Raisa jumped at the opportunity to help her friend, she was concerned about how the transplant would affect her own health.

photo: Instagram/selenagomez

"Because we were kind of in an emergency situation, I did everything in like a day," Raisa said.

The "Grown-ish" star even revealed she had to write a will. "There's no guarantee you're going to wake up."

Both procedures seemingly went as planned, until Gomez began "hyperventilating" in recovery afterward.

photo: NBC TODAY

The singer explained there was suddenly "so much pain," so doctors had to bring her back into surgery because her new kidney was turning around inside her body. 

"It was a six-hour surgery that they had to do on me, and the normal kidney process is actually two hours,” she said.

Gomez is "very thankful" the doctors were able to handle the complication with ease.

As for their recovery, Gomez got a space for herself and Raisa to be together and heal properly.

"You know, you're on bed rest, you're allowed to walk an hour a day. You can't do stairs or anything crazy," Gomez explained.

"It was hard because you constantly needed to ask for help," Raisa said, adding it was a very "humbling" experience.

At the end of it all, Gomez really just wants this experience to help others.

"I don't think what we went through is easy, I don't think it was fun," she said. "I just hope this inspires people to feel good, to know that there are really good people in the world."