Check out why blood induces fainting in some people.
Have you ever wondered why some people faint at the sight of blood?
Fear of blood is classified as a phobia, which is an intense irrational fear of something that causes your body to react by going into fight or flight mode.
But unlike other phobias, the fear of blood along with injury, and injection phobias can actually cause a person’s blood pressure and heart rate to go up and then suddenly drop, which can cause them to lose consciousness amongst other symptoms.
A certain nerve, called the vagus nerve, causes the drop in blood pressure when it is triggered by certain external stimuli like pain, dehydration, sudden fear, among other causes.
Scientists think that the nervous system reaction may be an evolutionary trait that lowers blood pressure at the sight of blood to prevent bleeding to death.
Researchers have found an effective way to cure certain phobias.
The phobic person has to tense up and then be exposed to whatever they are afraid of little by little.
In the case of a blood phobia, they show the phobic person a spot of red, and then a larger spot of red, then a picture of blood, then real blood.
Tensing up stops the drop in blood pressure from happening.
Around 3 or 4 percent of people have a blood, injury, or injection phobia.