Evolutionary Fainting: The Bizarre Mechanics of the Vasovagal Syncope

It is a common, often embarrassing phenomenon: seeing a drop of blood or a hypodermic needle causes an individual to instantly go pale, lose consciousness, and collapse to the floor. While it looks like a sign of weakness, fainting at the sight of blood is actually a radical, hardwired evolutionary survival tactic. This sudden collapse is known as a Vasovagal Syncope. When the brain perceives se...