That means more than a thousand Australians are on waiting lists for transplants, and hundreds will miss out every year.

Will Chapman is one of those on the list, and while he's waiting, he's encouraging people to think about the greatest gift of all.

At twenty years old Chapman should be in the prime of his life, but instead he is suffering from a terminal illness and awaiting his fate.

• Heart transplant teen's emotional farewell
• Miracle baby's mercy dash
• Little girl makes a big difference

“I miss normality. I miss being able to go to the beach most significantly. It played a major role in my life before I deteriorated to the extent where I couldn't make it down to the sand,” Chapman said.

No stranger to hospitals, he had open heart surgery at just three weeks of age.

It meant that for the first sixteen years of his life he lived a healthy, normal childhood.

“I have deteriorated to such an extent that I can't do anything for myself anymore. I have had all my independence stripped off me,” he said.

“I am breathless, hence the oxygen. I have left my career, my studies, I spend days sitting up here with my feet up to help the fluid retention. I am completely immobilised.”

To survive, Chapman needs a double lung and heart transplant.

Today Tonight's latest health stories

Last year there were only 337 organ donors in Australia - so for Chapman, although he hopes he gets his gift of life, it means someone else misses out.

He created a YouTube video to spread the word about organ donation.

“Since the video has been created we have had thousands register. We have had hundreds of thousands reminded about organ donation which is even better, and hopeful change some people’s minds about organ donation,” Chapman said.

More stories from reporter Madeleine Kennard

Professor of cardiology at RPA hospital in Sydney, Dr David Celemyer, is an organ donation advocate and Chapman’s doctor.

“Without a new set of heart and lungs Will is not going to survive very long. We don't think he will see Christmas, and it is now July. In fact he may only have two or three months to live,” Dr Celemyer said.

Although our national organ donation rates are up from previous years, there are 1600 patients already on this year’s waiting list. Last year 1001 people were given transplants, but if you do the maths it’s clear if we have the same donation rates this year, 600 people will miss out.

“I would encourage people to make the most of what they have. I hope that everyone lives their life to the fullest because one day we don't know when it is going to end for anyone - not just me, for anyone,” Chapman concluded.

• Share Life - www.sharelife.org.au
• Department of Human Services - www.humanservices.gov.au
• A Gracious Gift - www.facebook.com/pages/A-Gracious-Gift