Causes and Types of Brain Injury

Our brain weighs about 4 pounds and is made of extremely soft tissue that is floating in fluid in the skull. Brain injury can be called by different names, like concussion, shaken baby syndrome, and head injury to name a few. The brain can be hurt in many different ways; injuries to the brain are classified as non-traumatic or traumatic.

brain with neurons


The challenges someone with a non-traumatic injury faces can be different, but are often very similar to those faced by someone with a traumatic injury.

Examples of types of non-traumatic injuries include:

  • Hypoxic brain injury occurs where there isn't enough oxygen going to part of the brain.
  • Anoxic is when there is an absence of oxygen in a part of the brain.
  • Medical issue or disease such as contracting meningitis or encephalitis, infection or having a brain tumor.
  • Stroke (also known as Cerebral Vascular Accident or CVA) caused by bleeding from a blood vessel in the brain or when a clot forms in the blood vessel and reduces blood flow to the brain. An aneurysm is weak spot in the blood vessel that can cause a bulge and is at risk for bursting and causing significant bleeding.
  • Brain hemorrhage which occurs when there is bleeding in or around the brain.


Traumatic injuries fall into two categories:

  • Open head injuries are those in which the skull is crushed or seriously fractured.  Open head injuries also happen when the skull is penetrated, as in a gunshot wound.
  • Closed head injuries, in which the skull is not damaged, occur much more often, usually because of a car accident or fall.

The brain tissue is soft and can be compressed, pulled and stretched.  This can happen easily when there is a sudden change in speed such as in a car accident or fall.  The brain actually moves around inside your skull and can be damaged when it rubs or hits against the inside skull ridges.