This dilation happens almost at the same time as increasing body weakness. The weakness is usually on the side of the body opposite the hematoma. If consciousness continues to decrease, the pulse begins to slow. Breathing becomes difficult and the body gets weaker and less responsive to stimulation. Both pupils of the eyes become dilated and unresponsive to light, breathing ceases and finally death occurs.
Persons traveling at any increased speed are at risk for hematoma whenever the head is struck.
During impact, the brain moves around inside the skull. Bridging veins may tear, spilling blood into the subdural space. As people age, brains shrink slightly, so bridging veins are stretched. Thus, the elderly are more susceptible to this type of injury. People who have diabetes, epilepsy, alcoholism or any condition in which consciousness may suddenly be impaired are also more likely to fall.