@stvnews: An amber alert has come into force at hospitals across Scotland after blood stocks dropped to 'unprecedented levels'. The Scottish National Blood Transfusion Service wrote to hospitals last week to advise of the warning, which came into effect from 9am on Tuesday. In the coming weeks, staff will be urged to only use Type O blood when essential and to maximise use of alternatives to transfusions where possible. SNBTS says it aims to retain five to seven days’ supply across all blood groups, but stocks have consistently fallen below this target for several weeks. Group O, in particular, has fallen below two days on several occasions. #uk #Scotland #news #blooddonation #nhs #health #blood