Courtney Grayson feared for her life when the blood supply she urgently needed dropped so low there was just one bag left in NSW.
That one, precious bag of liquid gold was within reach - but it went to someone else.
Courtney, who was battling a life-threatening blood disorder, had to endure a scary wait.
"I needed a platelet transfusion. We were waiting for ages, Mum was like, 'where are they?' Then we found out there was one bag left in my type in NSW," recalled 17-year-old Courtney.
"I had to wait for another one. A pregnant lady that needed it got it before me.
"It was pretty dangerous for me with a life-threatening disease."
Courtney's experience, at age 13, brought home the gravity of a blood supply shortage and the importance of those public pleas for donors.
"One bag is just one person donating. That extra bag we needed so badly that day came from just one person," said Courtney, who is now living "life to the full" thanks to a bone marrow transplant two years ago.
The former Keira High School student plans to travel overseas, get work as a nanny and "just do the normal things like going to the beach on a hot summer's day".
Courtney has led a sheltered life since being diagnosed eight years ago with aplastic anemia - a condition where her body's bone marrow does not make enough new blood cells.
Patients experience fatigue, they bruise and bleed easily and are at high risk of infection.
Courtney has had to steer clear of sick people and crowds. Playing sport was out of the question.
"When I was nine I was getting bad bruising and headaches, so we went to the doctor and I had blood tests. It was straight up to the hospital that night."
Up until her transplant, Courtney needed regular blood transfusions - sometimes as many as four a week.
"I'd get sick a lot, I had to stay away from all those crowded places like shopping malls. I couldn't play sport, getting an injury would have been really dangerous," she said.
"I couldn't go out in the sun, I couldn't go see friends and I never had much energy. My immune system was bad. I got sick a lot."
Courtney said two years after her surgery she is "just getting back to normal now".
"That was really hard. I was in isolation in hospital for about seven weeks, only immediate family could come in. Then if there was one sign of a cough they were out.
"I was in that bed for so long that when I'd try to walk just for a minute I'd get really exhausted. Now I'm just starting to build my fitness levels up."
Courtney said she often felt like giving up but pulled through with the support of her family.
"My family are very positive. My mum was really strong for me.
"Everything is great now, but I can honestly say I wouldn't be alive if people didn't give me blood."
Courtney will be forever grateful to her donors.
"I really want to thank all those people who saved my life and let everyone know there are so many other kids out there that need blood," she said.
"People don't realise how important it is and neither did we, we were just like everyone else.
"It came down to that one bag - that one bag can keep someone alive."
The Australian Red Cross Blood Service has launched a Bleed-a-Thon to boost donor numbers in Wollongong this month. Call 131 495.