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National Brain Injury Information Center

What is a Brain Injury?

What is a brain injury?

Every 9 seconds, someone in the United States sustains a brain injury. Yet there are many misconceptions and gaps in knowledge among the general public. A brain injury affects how a person thinks, acts, and feels. The symptoms and impacts are wide ranging and can change everything about someone in a matter of seconds. This event affects both the survivor and their support network, so it’s important to keep some things in mind when interacting with a survivor. The most important things to remember are:

  1. A person with a brain injury is a person first.
  2. No two injuries are exactly the same.
  3. The effects of the injury are complex and vary greatly from person to person.
  4. The effects of the injury depend on factors such as cause, location, and severity.

Traumatic Brain Injury

A traumatic brain injury, also called a TBI, occurs when brain function is altered by an external force. This happens when something strikes the head or when the head hits something as the result of a fall, motor vehicle accident, assault, and more. There are many different causes of TBI and several different types. Learn more about TBI


A concussion is sometimes referred to as a mild traumatic brain injury or mTBI because they are usually not life threatening. A concussion is caused by a bump, jolt, or blow to the head that causes the brain to bounce around or twist in the skull. Although these are referred to as an mTBI, these are not necessarily mild injuries in terms of their symptoms and impacts on the survivor. Learn more about concussion.

Non-Traumatic Brain Injury

Non-traumatic brain injury (also commonly referred to as an acquired brain injury) causes damage to the brain as a result of internal factors, such as a lack of oxygen, exposure to toxins, and pressure from a tumor. Learn more about non-traumatic brain injury.

Functions of the Brain

The brain is made up of many parts, each with a specific and important function that impacts the way a person lives their daily life. So when there is an injury, it can have numerous effects on the life of the survivor. Learn more about functions of the brain.

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Living with a brain injury can require many different types of resources, strategies, and supports, the range of which can be tremendous. Sign up to join our monthly newsletter, and in addition to receiving news and resources from the brain injury community, we’ll give you a free copy of our guide: What to Expect After Brain Injury. This is guide can help survivors and caregivers navigate life post-injury.

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