THE growing popularity of tattoos and exotic holiday destinations among young Scots has been blamed for a decline in the number of people donating blood.

The number of new blood donors has fallen by 30 per cent in the past five years as the danger of exposure to blood-borne infections such as malaria and other tropical diseases has increased with Scots increasingly jet to hotspots such as Thailand, India, Mexico and South Africa.

Restrictions vary, but a spokeswoman for the Scottish National Blood Transfusion Service (SNBTS) said: "It can become a real problem for us, especially in summer."

Tour operators and airlines have reported a surge in bookings to Thailand from Scottish holidaymakers following terrorism in France, North Africa and Turkey, while anyone visiting Florida - which has also seen increased demand - would now be barred from donating blood for at least four weeks due to the risk of spreading Zika virus.

Potential donors are also asked to defer if they have have had a piercing or tattoo - including permanent or semi-permanent make-up - within the previous 12 months due to the risk of contracting diseases such as Hepatitis B from contaminated needles.

The SNBTS also blamed "busy lifestyles" for the drop.

The trend is reflected in statistics showing that while the vast majority of new donors - 96 per cent - are under the age of 55, blood supplies are disproportionately dependent on older, repeat donors. The over-55s account for more than one in five of Scotland's "active blood donors", with the 45-54 age group making up 23 per cent, indicating that "younger donors are not continuing to donate nor making a life-long commitment to saving lives".

The shortage of new donors emerged as a new international campaign was launched encouraging people to give blood and know their blood type.

The Missing Type campaign will run simultaneously in all four UK nations as well as 17 other countries worldwide including Australia, the United States, Japan, Brazil and Singapore.

There are a total of eight different blood types but the SNBTS found that only 38 per cent of people in Scotland knew theirs.

Blood type is not routinely recorded in a person's medical records unless they have previously undergone a blood transfusion.

However, someone who donates blood for the first time will be sent a blood donor card notifying them of their blood type.

Blood type O negative can be given to almost anyone, making it particularly valuable in emergencies. Just under one in 10 Scots have this blood type, but they make up 13 per cent of donors.

The most common type in Scotland is O positive - accounting for around 40 per cent of the population - while just 27,000 people have the rarest blood type, AB negative.

SNBTS wants more people to be aware of their blood type so that they can respond to appeals when stocks of particular types run low.

A spokeswoman said: "Blood stocks can vary significantly at any one time. Seven out of the eight types can be in strong supply, but one of the eight can suddenly become very low and obviously we would want people coming forward to donate who have that particular type.

"Blood has a relatively short shelf-life so we don't want to waste people's time and end up having to throw away surplus blood."