A terminally ill Missouri woman is planning to go to Switzerland to end her own life in a physician-assisted death while she is still physically capable of making the trip.

Gayle Hendrix, a 79-year-old mother of two from Cape Girardeau, was diagnosed with lupus and interstitial lung disease four years ago and says her lung capacity continues to worsen.

"I’ve had a great life, and I want to have some dignity when I’m going to the next phase," she told 12 KFVS.

After her diagnosis, she says her shortness of breath continued to become worse and was breathing heavily even on flat surfaces.

PHYSICALLY HEALTHY DUTCH WOMAN DIES BY ASSISTED SUICIDE AT AGE 29

"My friends will say, 'But you don’t look or sound or act like somebody who is near death.' But I am dying, and that's what I want to control," she said. 

"I don't want to get to the point of, 'This is existing, not living,'" Hendrix continued. 

Hendrix must use an oxygen machine and can only walk short distances.

She had lived an active lifestyle before her diagnosis, which included traveling a lot for work, hiking and riding a bicycle.

"She was always busy, always … She always either had three jobs or she was going somewhere, like to concerts or festivals," her daughter, Charlene Foeste, told the news station.

Hendrix, who is originally from North Carolina, is now a retiree after having had a career in human resources. She also lived in other locations during her career before returning to Missouri.

"I would love to say I was a poet, a painter and a musician ... I have nothing in that arena," Hendrix said with a laugh. "So, I think that's why I took up walking because I can walk. I was an avid walker, anywhere from three to five miles a day ... every day up until about three years ago."

Following her retirement, Hendrix grew bored and went back to work during the pandemic as a contact tracer. She recently retired again, as she prepares for her next chapter.

"It is going to be hard, but I know that, and I know sort of what to expect and what the end result is going to be for sure," Foeste said.

Hendrix and Foeste will board an airplane this week for a flight to Switzerland where Hendrix will end her life on Sept. 26 through assisted suicide.

"When I started seeing more and more decline, like monthly, I can tell this is not as good as it was last month. I knew then if I wanted to do it when I’m still able to walk in and still make the trip, then I need to do it soon," Hendrix said.

Physician-assisted death is legal in the U.S. in ten states and Washington, D.C. All but two of these places have residency requirements, with the exceptions being Vermont and Oregon.

But Hendrix is choosing to end her life in another country because, among other rules and regulations, a patient must have six months or less to live to undergo assisted suicide where it is legal in the U.S.

"I don't want to wait that long," Hendrix said. "I don't want to get that sick."

Even before her diagnosis, Hendrix had spent decades advocating for the right to assisted suicide, including by becoming involved with groups like Compassion and Choices, a nonprofit that works to increase access to so-called death with dignity.

She filled out the paperwork for her assisted death this past spring and was planning to make the trip to Switzerland in August, but she had to push her timeline back due to a lack of open spots for the procedure during that time.

"They put an IV in your arm and the first medicine that goes through puts you to sleep and the second one stops all body functions," Hendrix said. "They have some kind of button on the IV, you have to be able to push that button and that starts the fluid. In five minutes it’s done."

When her life ends, she will be cremated and her remains will be shipped back to Missouri in a couple of weeks.

Hendrix said she is not nervous about the trip, but acknowledges the impact her death will have on her family.

"It's a huge loss, a huge loss for us," Foeste said. "It's not going to be the same. It’s just not."

Hendrix said she has had tough conversations with friends and family who do not support her decision to end her life through assisted suicide, including some who believe what she is doing is morally wrong.

"Some of them are religious, and, you know, have some views, but I think because I've been open about it for so long around people, they weren't shocked," Hendrix said.

Her daughter is among the people who do not support her decision to end her life.

CALIFORNIA SENATOR PUSHES 'DEATH ON DEMAND' ASSISTED SUICIDE MEASURE

"I can't say I agree with her decision, I don't," Foeste said. "But, it's not my choice. I do love her and support her and there's no way on the planet my mom is going to do this alone, no way."

"I love her and support her 100%, no matter what," Foeste added. "She knows that, my kids know that, and I just wish more people were like that."

Hendrix said she is aware she could potentially miss out on more quality living, but does not want to run the risk of ending up in a hospital bed.

"I just am peaceful about my decision, and it’s the right thing for me and my body," Hendrix said.