9 Revelations From Selena Gomez and Francia Raísa's 'Today' Kidney Transplant Interview

The pair opened up about the experience, which began five years ago when Gomez was diagnosed with autoimmune disease Lupus, in a lengthy interview with Savannah Guthrie.

Below are the nine most interesting revelations from the sit-down.

This past summer, Gomez's kidneys had begun to shut down, and she was just weeks away from dialysis. "I didn't realize how much it was affecting my body," she said. "I had arthritis, my kidneys were shutting down, my mentality was just to keep going."

"One day she came home, and she was emotional," said Raísa, an actress on the upcoming Freeform show, "Grown-ish." "I hadn't asked anything. I knew that she hadn't been feeling well. She couldn't open a water bottle one day, and she chucked it and just started crying. And I said, 'What's wrong?' And that's when she told me."

"She lived with me in this interesting time where my kidneys were just done. That was it," Gomez said.

Raísa said Gomez tearfully told her the donor list was seven to 10 years long. "It just vomited out of me," Raísa said. "I go, 'Of course I'll get tested.'"

Raísa insisted, saying, she called Gomez's assistant and said, "'Give me the information. I want to do this.'"

"I didn't want to ask a single person in my life," Gomez said. "The thought of asking somebody to do that was really difficult for me. She volunteered and did it. Let alone somebody wanting to volunteer, it is incredibly difficult to find a match. That fact that she was a match, I mean, that's unbelievable. That's not real."

Raísa immediately began the process of having her blood and urine tested. She also underwent physical and psychological evaluations.

"With our situation -- because we were kind of in an emergency situation -- I did everything in like a day, and usually, the process takes like six months, so it was really fast," she said.

Just because Raísa volunteered to be Gomez's donor doesn't mean she wasn't still scared.

"I had to write a will, which was scary, because there's no guarantee you'll wake up," she said. "My mom didn't want to be there until I woke up. She loves Selena, and so she was torn."

Gomez said she got out of her two-hour surgery and was resting in her room when she began hyperventilating.

"I started to attempt to fall asleep, and in the middle of that process, I started hyperventilating, and there was so much pain there," she said.

"My teeth were -- I was like grinding. I was freaking out," she added.

Doctors took Gomez back into surgery because her new kidney was turning around inside her body. The surgery lasted another six hours.

"I am very thankful that there are people who know what to do in that situation," Gomez said."

"What I wanted more than anything was that we were together, so I actually got a space for us to be in together," Gomez said. "You're on bed rest, you're allowed to walk an hour a day. You can't do any stairs or anything crazy."

Raísa added, "It was hard because you constantly needed to ask for help. I think one of the most humbling experiences was needing help to put on underwear. We couldn't take showers by ourselves. It was a really brutal process."

When asked if she felt Raísa saved her life, Gomez said yes, adding that she had gotten to the point "where it was life or death."

"As soon as I got the kidney transplant, my arthritis went away, my lupus was about a three to five percent chance it'll ever come back, my blood pressure is better, my energy, my life has been better," she said.

"I just really hope that we can help somebody, I really do," Gomez said tearfully. "I don't think what we went through is easy. I don't think it was fun. I hope that this inspired people to feel good to know that there is really good people in the world."