An injury that takes place between the skull and the dura mater or layers of inner connective tissue that protects the brain: The epidural hematoma can be caused by a ruptured meningeal artery after a fracture of the skull when it is hit excessively hard.

The damage to blood veins between the dura mater and the arachnoid; spider-like or web-like fibers of tissues of the membranes: The subdural hematoma is often caused by blunt traumas; such as, from blows to the head by boxers or in elderly patients who fall out of bed and hit their heads against something hard.