Ellie Chin is too young to know she has relied on the goodwill of hundreds of blood donors, some before she was even born, to stay alive.
The one-year-old from Thornlie has the genetic blood disorder thalassaemia, which affects the production of haemoglobin, the part of red blood cells that keeps the body supplied with oxygen.
Diagnosed when her mother Joan was 32 weeks pregnant, Ellie began receiving donor blood in utero and still needs monthly blood transfusions at Princess Margaret Hospital to stay well.
Mrs Chin said her family never took for granted the generosity of blood donors who help Ellie manage, despite her condition.
"We feel blessed that she is so well looked after and it's so manageable, so for us the donation of blood is such a massively emotional thing," she said.
The Australian Red Cross Blood Service is warning it urgently needs more people to give blood as reserves plummet to critical levels.
Spokeswoman Kathy Bowlen said yesterday there was only 2.2 days' supply of all blood types across the country.
"We aim to have six days' supply at all times to ensure we have blood for patients who need it, so this is a real concern for us," she said.
Colds and flus were stopping more regular donors coming in.
This affected cancer patients, people having surgery, pregnant women and unborn babies who needed donated blood.
Call 13 14 95 or visit donateblood.com.au.