Chapel Hill, N.C. — Cystic fibrosis used to steal the lives of children before their teens. New medical treatments, however, have patients living well into adulthood.

Joy Cook, 23, suffered from cystic fibrosis for several years before she knew what it was.

“I was diagnosed when I was 7. I'd been sick a lot as a child,” she said.

Dr. Peadar Noone, a pulmonologist at the University of North Carolina at Chapel Hill, said the most serious symptom of cystic fibrosis is mucus building up in the lungs.

“The air passages become built up with bacteria and as time passes, that really takes its toll on the airways and damages the lungs,” Noone said.

New treatments like breathing a simple aerated salt solution can help clear the lungs.

In December 2006, when Cook was a junior at UNC, these new treatments were too late to reverse the damage done.

“That's when we start thinking things like lung transplant,” Noone said.

Fortunately, Cook didn't have to wait long for a donor's lungs, just 24 hours.

“I remember feeling better as soon as I was conscious enough to be awake,” Cook said.

With few complications, she steadily grew stronger. She was even able to  join a recent fund-raising walk to benefit cystic fibrosis research.

“I mean, I feel like I just want to do everything I can with them (lungs) that I couldn't do before. So the walk was in the spring and I just always seemed to be sick in the spring,” Cook said.

Cook said she wants the donor's family to know just how much she appreciates their gift.

“I'm extremely, extremely thankful and enjoying every second that I've got,” she added.