The Rugby World Cup may have seen a rise in blood pressure for some teams' fans, but it has also seen a decrease in blood donations.
The New Zealand Blood Service says in the first week of the tournament, donations were down by around 100, or 3 per cent.
NZ Blood Service spokesperson Paul Hayes says the small decline is not unusual, but regular donations are vital to keep up with demand.
"Regular donations are critical because blood has a shelf life. Red blood cells only last 35 days and platelets last just 5 days," Mr Hayes says.
Around 3,000 units of blood are required each week to meet demand, the equivalent to nearly the entire capacity of North Harbour Stadium donating blood between now and the end of October.