Originally Posted by
Rhlor
The Warcraft Encyclopedia/Blood Elves
he Consequences of Addiction
Blood elves no longer truly consider themselves high elves, and they tend to have different priorities and behaviors than their high elf kindred. Unlike high elves, blood elves have decided that in the absence of the Sunwell, they will feed their hunger for arcane magic by draining that magic from alternative sources.
However, some basic similarities remain between blood elves and high elves, for both groups belong to the same race. As with high elves, most blood elves are not spellcasters. Blood elves do not drain magic in order to engage in spellcasting, but simply to feed their addiction to arcane magic. Gaining this magic on a reasonably regular basis has not given immortality to the blood elves, who are just as prone to illness, injury, and age as their high elf brethren. To date, there have been no observations of a significant difference between blood elf and high elf lifespans.
On several occasions after the Sunwell's defilement, Kael'thas publicly asserted that his people would die unless they found a new source of magic. There can be no doubt that withdrawal from prolonged exposure to arcane magic is a very unpleasant process: to this day it is not impossible that a high elf might choose to give in to the addiction and become one of the blood elves. Technically, though, the prince was mistaken. According to the top priests and medics on Azeroth, the only high elves who perished due to the Sunwell's loss were the very old, the very young, and elves who were already in poor health.
This is not to say, however, that withdrawal from magic would leave the blood elves unharmed. On the contrary, permanent mental or physical damage is possible.
Even so, the prince's relatively quick acceptance of dire measures (e.g., draining magic from demons) is by no means characteristic of blood elves in general. The blood elves of Outland have by now discovered Kael'thas' agreement with Illidan, and they have for the most part become convinced of its necessity. Most blood elves still live on Azeroth, though. Few of these elves know of Kael'thas' pact with Illidan, and many would be horrified if they discovered it. Draining magic from small mana-bearing vermin is a far cry from draining magic from demons. Yet, as their hunger grows, blood elves--particularly those in Outland--are becoming increasingly inured to the things they must do in order to obtain more magic.