There are two basic types of brain injuries: open and closed.
CLOSED BRAIN INJURIES are the most common, and as the name suggests, they cover any brain injury that doesn’t involve a break in the skull. The fact that your brain is not exposed can make infection less likely, but these injuries can still be incredibly serious and even life-threatening.
CONCUSSION
Concussions are one of the most common types of closed brain injuries. These wounds happen when a significant force or impact slings your brain into the inside of your skull. It’s possible to get a concussion even if your head never hits anything, especially in car wrecks, when your body is getting slung around with tremendous force.
EDEMA
Edema is a secondary condition that arises as the result of a traumatic brain injury. After an injury (such as a concussion), the brain may swell, putting pressure on the tissue and even crushing parts of the brain against your skull. This swelling is called edema, and it can cause serious damage if the pressure isn’t alleviated.
HEMATOMA
A hematoma is a condition in which blood pools in your brain as the result of a ruptured blood vessel. This can also put pressure on your brain and may start to damage some of the tissue there.
DIFFUSE AXONAL INJURY
Your brain is held in place within your skull by long bands of tissue that connect your brain to the bone. When those connective tissues get torn, it’s called a diffuse axonal injury, or DAI. As you might imagine, since these tissues are connected to so many parts of your brain, these injuries can cause significant damage in many areas of the brain.
OPEN BRAIN INJURIES involve some crack or hole being created in the skull, exposing the brain. These injuries can be more susceptible to infection, since viruses and bacteria can now get to your brain more easily. They also leave your brain vulnerable to further trauma, since you don’t have the protection of your skull in that area any more.
SKULL FRACTURE
Skull fractures are a common result of car accidents and falls in which you hit your head. These fractures can heal over time, but they may cause additional damage to your brain or complications in your recovery.
GSW
Gunshot wounds to the head can be incredibly dangerous, if the victim manages to survive at all. Bullets can introduce germs directly to the brain tissue, and the resulting open injury can leave a victim at enormous risk of infection. In addition, the concussive force of a bullet passing through the body damages tissues in a wide radius around the actual shot trajectory.