Why We Faint (When Other Animals Don't)

Humans are unique in the animal kingdom for fainting from fright due to a combination of an upright stance and a large brain. When humans experience danger, their blood pressure spikes, but it can drop too low afterward, causing fainting. This is because our brains require a significant amount of blood, and our upright posture makes it challenging for blood to reach the brain. While fainting can lead to injuries, the traits that cause it have also allowed humans to thrive globally.

What unique combination of traits allows humans to faint from fright?

How does the upright stance of humans affect blood flow to the brain?

What percentage of blood flow does the human brain require compared to other animals?

What are some common triggers that can cause humans to faint?

What are the potential consequences of fainting for humans?