What actually happens to your body when you faint?

Question

What actually happens to your body when you faint?

Answer 1

"Fainting is a sudden (and generally momentary) loss of consciousness, or blacking out, due to a lack of sufficient blood and oxygen reaching the brain. The first symptoms a person feels before fainting are dizziness, a dimming of vision, or brown-out and feeling hot. Moments later, the person's vision turns black and he or she drops to the floor (or slumps if seated in a chair).

Factors that influence fainting are taking in too little food and fluids, low blood pressure, hypoglycemia, growth spurts, physical exercise in excess of the energy reserve of the body, and lack of sleep. Even standing up too quickly or being in too hot a room can cause fainting."