We've probably all thought about giving blood, and many of us will have done it, but there's a lesser known donation that can be given - blood platelets.
These blood cells are needed by many cancer patients and others to help their blood clot.
And there's an increasing need for donors as supplies are being brought in from outside Northern Ireland.
Four-year-old Oscar Knox had an eight-hour nosebleed because his body doesn't make enough platelets.
It's due to his having neuroblastoma, a rare form of childhood cancer, and because of it Oscar needs platelets about once a week.
"He would have been bleeding for four, six, eight hours even and as soon as he gets his platelets put up by the drip the bleeding can stop in10 minutes," said Oscar's mum, Leona.
There are about 58,000 blood donations last year but only 4,674 platelet donations.
Now the Knox family want to do now is to raise awareness that platelets can be donated as well as blood so patients like Oscar can continue to receive treatment at Belfast City Hospital.
Leona continued: "You have to understand what this means to people like Oscar.
"If he didn't have platelets he wouldn't be able to continue his fight against cancer and as far as we're aware 94% of people here in Northern Ireland don't donate platelets or blood so our message is please, if you can, please do it."