NHS Scotland has called for donors of certain blood types to come forward as national stocks have fallen to "unprecedentedly low levels".
Increased levels of need from hospitals, combined with an abnormally high level of unfilled appointments at blood transfusion centres, has caused a UK-wide shortage alert to be issued for the second time ever.
Though NHS Scotland has said it is not "directly affected" by ongoing shortages in England, health authorities are calling on the public to make extra efforts to donate over the summer.
Blood donation in Scotland is run by the Scottish National Blood Transfusion Service, and provides information about how to donate blood at www.scotblood.co.uk.
Women can donate blood once every four months, and men can donate once every three months.
The service aims to keep at least six days' supply of each blood type on hand, but at present, four of the eight blood types are below this level.
Stocks of O+ and B+ blood are at five day supplies, while O- and B- are down to four days.
The shortage of O- donors, whose blood can go to recipients of any blood type, is of particular concern.
However, Professor Marc Turner, director at the Scottish National Blood Transfusion Service, said the shortage is not "critical".
He continued: “NHS Scotland is not directly affected by the shortage of blood group O red cells in England and therefore we are not in amber alert and have adequate blood stocks to meet clinical demand.
“However, we are asking people to continue to make an extra special effort to donate over the summer holiday period when blood stocks are traditionally low.
“On average, Scotland needs to fill around 3,500 appointments each week and there are currently over 1,800 appointments still to fill in donor centres over the next two weeks.
“Our donor centres in Aberdeen, Dundee, Edinburgh, Glasgow and Inverness still have a lot of appointments available which can be booked at www.scotblood.co.uk.”
Blood stocks in England have reached extremely low levels, with stocks of O- blood hitting just 1.6 days, and all blood types together sitting at 4.3 days.
Hospitals south of the Border are being asked to reduce their use of O- blood as much as is possible.
