For 66-year-old Bay of Plenty man Noel Hall, giving blood is a walk in the park.
The retired engineer has been a regular donor for more than 30 years.
He's never needed a blood transfusion himself, he's just been happy to have a way of helping people less fortunate.
"They've always wanted it and I've been able to give it," he said. "It's no inconvenience for me."
As his career has taken him around the country, he's hunted out centres and blood drives at which he can donate his "standard" O+ blood.
For the past few months he has gone to the Tauranga Blood Donor Centre every few weeks to donate plasma. That involves a different process to donating red blood cells and requires specialist equipment, available only at the main donor centres.
Red blood cells are used to treat patients with chronic anaemia from the likes of kidney failure and cancers, and acute blood loss from trauma or surgery. Plasma-only blood is used to control bleeding in patients after trauma or a transplant.
"I want to keep donating as long as possible," Mr Hall said.
The Tauranga Blood Donor Centre has had a marked increase in plasma donations in the two years it has been able to take plasma but its red blood-cell donations have decreased in the past five years. Team leader Annemarie Pidwell said the drop was due to reduced demand.
"Doctors have got smarter and learned more," she said. "At our end, we're trying to not waste as much so we've tried to change the culture of people just turning up ... and got them to come in on an appointment-based system instead."
Tauranga was the first centre to pilot an appointment process. It meant it collected only the blood it needed, Ms Pidwell said.
The centre had seen a 600 per cent increase in plasma donations over the time it had been able to receive them.
NZ Blood Service spokeswoman Asuka Burge said demand for red blood cells dropped due to a conservation project led by district health boards and the Blood Service in 2010.
The project encouraged medical practitioners to reduce the number of transfusions, because patients were frequently being over-transfused.