It is estimated that 8 million people sustain head and brain injuries each year in the United States and that at least 2 million of those will be permanently injured. Auto accidents are a leading cause of head and brain injuries.

Accidents are the leading cause of death and disability of men under 35, with over 70% of accidents involving head injuries and/or spinal cord injuries. Many brain injuries are the result of bleeding, twisting or tearing of the brain tissue. Brain injury can also occur when the head has been struck, usually by hitting an object like a windshield or by a sudden acceleration/deceleration movement such as in whiplash where there is no direct external trauma to the head. Brain injuries can occur at the time of the accident or develop over time as a result of tissues bleeding and swelling within the head.

The brain is enclosed in the cranium or skull and is an approximately three-pound mass of gray matter. It coordinates and controls bodily functioning, interprets sensory impulses, and is the center of emotion and thought. The brain has three main areas: the cerebrum , the cerebellum and the brain stem. The cerebrum is where most of the thinking takes place. It has four lobes and two hemispheres: the right and the left. The right hemisphere controls visual memory, copying, drawing and rhythm. The left hemisphere is often the dominant one and controls speaking, writing, calculating and reading. The frontal lobe, which is located near the front of the cranium, is sometimes damaged in accidents. The frontal lobe is considered to be the area for the emotional and personality traits. The cerebellum controls balance and coordination. The brain stem connects the brain to the spinal cord. It controls breathing, heart rate, alertness and consciousness. Although the skull protects the brain, its inner surface contains ribbing and bony structures. If the brain moves inside the skull, it can be pushed into these bony structures causing injury.

There are many kinds of brain or head injuries. Some examples are:

Contusions or concussions - When the brain is bruised by hitting the cranium, a contusion or concussion occurs. This injury can lead to vomiting, dizziness, headaches and problems remembering or concentrating. It can have long term effects.

Anoxic brain injury - An anoxic brain injury occurs when blood flow to the brain is disrupted. It is caused by a lack of oxygen to the brain usually by swelling and bleeding of the brain tissue.