The Irish Blood Transfusion Service is urging donors to make a special effort to give blood in the run-up to Christmas.
The IBTS says it needs 15,000 donations over the coming weeks to maintain the blood supply.
It is to run additional Saturday and Sunday donor clinics before and after Christmas to ensure there is blood available for patients.
Details of where and when blood can be donated is available on the IBTS website.
Meanwhile, Minister for Health Leo Varadkar has said that a review is under way into whether the ban on gay men donating blood could be lifted.
He said the review is expected to be presented to his department within the next two months.
