Alex Pangman, a Canadian swing singer impressing audiences after undergoing two double lung transplants in the past decade, is singing the praises of the 'heroes' who made her career possible as she urges others to sign up as organ donors too.

Pangman has cystic fibrosis, a debilitating inherited disease that causes internal mucus buildup, lung infections and early death. But to see her perform at the Sun Life Financial Uptown Waterloo Jazz Festival, few would be able to tell.

Peer closely, however, and you might spot the small green ribbon she wears to raise awareness about a personal cause.

Pangman had a double-lung transplant in 2008, but her body rejected it after a few years. She then received another transplant in 2013.

Pangman said imagining herself back on the stage aided her recovery.

"I certainly kept my eye on the prize of singing again when I was really unable to walk up a flight of stairs without a tank of oxygen," Pangman told CTV Kitchener.

Pangman's lungs are now at 95 per cent capacity, and her voice is so strong that most of her Waterloo audience had no idea of her past health problems.

The fans that follow Pangman are happy she's back on stage, and giving a voice to organ donation.

"You're sitting there listening to her and you would not know," said Pangman fan Phil Grosvenor. "I'm thankful that she shares the back story because there are a lot of Canadians that still are reticent about signing that donor card."

Pangman hopes that by sharing her story, she'll inspire others to sign up for their own donor card.

"It's a beautiful gift, and my donors -- because there are two of them now -- they're really my heroes," Pangman said.

With files from CTV Kitchener.