BLOOMINGTON--From the outside, 14 year old Mikahla Thornton looks like anyone her age.
But there's one defining factor people can't see.
"When I was nine years old I went into severe heart failure and that's when they put me on the heart transplant list," said Thornton.
Thornton was born with hypertrophic cardiomyopathy, a life threatening condition limiting her ability to walk, run and play.
"Basically her heart muscle was too thick to relax so it didn't relax well and that caused her blood to back up into her liver," explained her mother Wendy Montgomery.
For Mikahla, the future looked grim, until the family received a phone call from doctors saying they had a heart available.
"I was at the breaking point," recalls Thornton. "So I just think if I wouldn't have gotten the call that day, how much longer would I have been before I had died."
While doctors didn't tell her much about her donor, she knows the heart came from a nine year old boy.
"I think about it every day," said Thornton. "I cry sometimes because it's like a big thing."
Thornton had her surgery on April fifth 2007.
A day she calls a second birthday.
But the date also brings back loving memories of a boy she never met, but is forever grateful for the gift he gave.
"I celebrate it with happiness. You know me and my family we go out to eat. I get gifts and stuff because we call it a 'rebirth birthday,'" explained Thornton. "But then I think about his family. He died and gave me a second chance."
Now Thornton is encouraging others to give the gift of life.
She even partnered with Secretary of State Jesse White last year to promote organ donation.
"He decided I was going to be the spokesperson. So he just called my mom one day and asked, 'Mikahla want to do a commercial?"'
As her life goes on, Thornton hopes to encourage more loving hearts to make the decision that ultimately changed her life.
Thornton wants to become a nurse when she grows up.
She's planning to work at St. Louis Children's Hospital, where she received her heart transplant.