TBI vs. Concussion: What's the Difference?

Medically Reviewed By William C. Lloyd III, MD, FACS
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Asian American man holding front of head in pain

There are so many ways you can hurt your head. You can knock it against an open cupboard door, fall on the ice, be hit with an object, or get knocked on the head while playing a sport, to name just a few. While not all knocks to the head cause a traumatic brain injury (TBI), in 2014, there were almost 3 million emergency room visits, hospitalizations, and deaths related to TBIs in the United States. Most TBIs are concussions—mild TBIs. Up to 3.8 million concussions a year occur in the U.S. So, what is the difference between a TBI and a concussion? A concussion is a TBI, but a TBI isn’t necessarily a concussion.

Concussion Symptoms

A concussion occurs when your brain moves and hits the inside of your skull, causing bruising. The amount of brain damage determines concussion severity. 

Symptoms of a concussion can begin right away or they may come on gradually, over a few hours after the accident. You don’t have to lose consciousness for a concussion to occur, although you might. 

Symptoms may include:

  • Headache or feeling pressure inside your head

  • Confusion, disorientation, and memory problems

  • Dizziness and nausea

  • Slurred speech

  • Fatigue, like you can’t stay awake

  • Inability to sleep

  • Behavior changes, such as irritability, uncontrolled crying, or anxiety

  • Seizures

TBI Symptoms

Moderate to severe TBIs are more serious injuries than concussions. They can be caused by a severe blow to the head or a penetrating injury, like a bone from a fractured skull or a bullet. An open TBI refers to an injury where the skull is damaged and there is an opening in the bone. Closed TBIs occur without any open injury (opening) to the skull. 

TBI symptoms depend on the type of injury and the severity. For a serious injury like a bullet wound, symptoms are obvious and immediate. But other injuries—even a fractured skull—may cause delayed symptoms. They could include:

  • Losing consciousness

  • Nausea and vomiting

  • Head pain

  • Seizures

  • Fluid draining from the ears or nose

  • Confusion

  • Memory loss

  • Loss of coordination

  • Loss of sensation in the fingers and toes

  • One or both pupils are dilated (wider than they should be)

  • Agitation and irritability

  • Slurred speech or speech that doesn’t make sense

Causes of Concussions and More Severe TBI

Any blow to the head or severe shaking of the head can cause a TBI. The most common causes are:

  • Falling. The higher the height, the more serious the brain injury can be. However, even falls from a lower level, like rolling off a bed, can result in a TBI.

  • Car and bicycle accidents. Brain injuries can be caused by an impact to the head or the sudden jolt of the collision.

  • Sports injuries. Some sports are well known to cause concussions, usually contact sports like football or soccer (from heading the ball), but any sport where you could fall or come into contact with another player can cause a TBI.

  • Violence and combat. Being near an explosion can cause a TBI, as can penetrating wounds from shrapnel or bullets. Also, domestic violence, including shaken baby syndrome, are common causes.

Diagnosing TBIs

Diagnosing a concussion can be difficult as symptoms can be vague and differ from person to person. But TBIs, including concussions, are medical emergencies. If you have received a blow to the head and show any signs of a TBI, it is important that a doctor evaluates you. Concussions, even though classified as mild TBIs, can cause serious complications, especially if you sustain another blow to the head before you are fully healed.

Your doctor will take your history, including how and when the injury occurred, and then do a physical exam. Concussions are usually diagnosed based on the injury and your symptoms. You may be tested for memory and language, as well. If your doctor has concerns, you may be admitted to the hospital for observation. 

A commonly used diagnostic tool for more severe TBIs, called the Glasgow Coma Scale, allows your doctor to determine the seriousness of the injury. The doctor will evaluate how you respond to questions and requests, such as:

  • How do your eyes respond? Do you open your eyes spontaneously, only when asked, in response to pain, or not at all?

  • Do you speak normally? Are you confused or disoriented? Are you making sounds, not words? Do you make no sounds at all?

  • Can you obey commands to move? Do you move only when something is painful? Do you move abnormally? Do you not move at all?

If your doctor suspects a TBI, you may undergo:

  • Imaging tests of your head, either a CT scan or MRI

  • Intracranial pressure (ICP) monitoring, which involves inserting a probe into your skull to measure the amount of pressure

Treating Concussions

The only way to treat a concussion is by allowing your brain to rest. A repeat blow to the head before the initial one has healed can result in second-impact syndrome, which can be fatal. Most people understand the need to not do anything physically taxing while recovering from a concussion, but there are other, less obvious activities that must be stopped or limited during the recovery period. They may include:

  • Playing video games

  • Watching TV

  • Working on the computer (school or work)

  • Texting

  • Reading

You may also have to avoid areas that are highly stimulating with loud noise and bright lights. Your doctor will tell you what timeline to follow in terms of gradually reintroducing the activities as you heal.
Ask your doctor about pain relievers if you are experiencing headaches.

Treating Moderate-to-Severe TBIs

Initial treatment will depend on what caused the injury. Surgery may be necessary to repair injuries from a fractured skull, to remove blood clots, or to make an opening in the skull if the brain swelling is severe. Your doctor may also choose to put you in a medically induced coma, to allow your brain to rest while it tries to heal. Other treatments could include medications called diuretics or corticosteroids, which reduce pressure on the brain, and antiseizure medications.

Once the initial crisis is over and you’re healing, you may be referred for rehabilitation services. This allows you to work with other healthcare professionals, like physical therapists, occupational therapists, speech pathologists, and more.

Life After a TBI

A TBI, as the name implies, is traumatic. It can take several months or longer to fully recover. Unfortunately, some people never return to their previous level of functioning after a severe TBI. It’s important to get the support you need during your recovery phase and to not try to rush the process. If you are recovering at home, speak with your healthcare team about steps you can take to heal as well as possible.

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Medical Reviewer: William C. Lloyd III, MD, FACS
Last Review Date: 2021 Sep 8
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THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.
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