There are many causes of an ABI. Traumatic Brain injury is caused by physical traumas, for example an accident, neurosurgery, head injury or even an assault. Brain injury can also be caused by non traumatic circumstances such as a stroke, brain tumours, infections, hypoxia, ischemia or substance abuse. Brain damage caused by neurodegenerative disorders are not classed as an ABI. Injury is referred to as either open or closed. A closed injury is when the brain has been damaged from the brain being bounced around the head or severe shaking, for example when in a road traffic accident. Open brain injury is a lot less common than closed and is incurred when a foreign object enters the brain, usually fracturing the skull. An example of this is a bullet entering the brain. These injuries are usually more localised and result in specific damange to the brain. Although traumatic brain injury is classed as part of ABI, it is different as ABI takes place at a cellular level and can affect different zones within the brain. Traumatic Brain injury will only affect the area of the brain in which the trauma occured.
The level of a persons consciousness is often initally afected by ABI. Impairments from ABI can be mild, moderate or severe. Impairments usually effect more than one area such as, speech,