Traumatic Brain Injury: Causes, Symptoms & Treatment

Brain injury image
A concussion is a traumatic brain injury caused by the brain violently bouncing or twisting inside of the skull. (Image credit: Shutterstock)

Traumatic brain injury (TBI) is damage to the brain caused by an outside force. It is a very common brain condition. In 2010, there were about 2.5 million TBI-related deaths, hospitalizations and emergency room visits, according to the Centers for Disease Control and Prevention (CDC), and more than 50,000 people died due to TBI. 

Among TBI-related deaths from 2006 to 2010, men were about three times as likely to die as women, according to the CDC, and rates were highest for people 65 years and older. 


Outside forces that can cause TBI include bumps to the head, foreign objects penetrating the skull or the brain violently bouncing or twisting inside of the skull due to a sudden jolt. Concussions are classified as a mild or medium TBI. 

Those more susceptible to TBI are children, especially newborns to 4-year-olds; young adults, especially those between ages 15 and 24; and adults age 75 and older, according to the Mayo Clinic. "It's critical to protect children from head injuries because their brains are still developing and the tissue isn't fully formed," Dr. Joseph Rempson, co-director of the Center for Concussion Care and Physical Rehabilitation at Overlook Medical Center's Neuroscience Institute in Summit, New Jersey told Live Science. "According to research, the brain continues to evolve until an individual is 20 to 25 years old. If a child injures his/her brain they may not reach their full developmental potential from a memory or cognitive standpoint."

According to the CDC, between 2006 and 2010, falls accounted for 40 percent of all TBIs in the United States. Unintentional blunt trauma, such as being hit by an object, was the cause of about 15 percent of all TBIs. Motor vehicle crashes were the third leading cause, accounting for 14 percent. About 10 percent of all TBIs occurred during an assault.


It is important to remember that not all TBI cases make the injured person black out or lose consciousness. According to the National Library of Medicine, symptoms of TBI may not be apparent right away and may take days or weeks to materialize. 

Symptoms of TBI can be hard to recognize because they differ, depending on the severity of the brain injury. According to the National Institute of Neurological Disorders and Stroke (NINDS), mild TBI may exhibit blurred vision or tired eyes, headache, confusion, lightheadedness, bad taste in the mouth, dizziness, loss of consciousness for a few seconds or minutes, ringing in the ears, fatigue or lethargy, a change in sleep patterns, behavioral or mood changes, and trouble with memory, attention, concentration or thinking.  

Moderate or severe TBI, according to the NINDS, may also include the symptoms mentioned above, but may also include a headache that gets worse or does not go away, convulsions or seizures, slurred speech, an inability to awaken from sleep, repeated vomiting or nausea, weakness or numbness in the extremities, dilation of one or both pupils of the eyes, loss of coordination, and increased confusion, restlessness or agitation. 

Symptoms in children can be even harder to diagnose because children often have trouble expressing how they feel. Parents and caretakers should look for any strange behavior, such as appearing dazed, loss of interest in favorite toys or games, unusual clumsiness or unsteady walking, listlessness, crankiness, easily becoming tired, excessive crying or changes in eating or sleeping, according to the Mayo Clinic. Ideally, children should be taken to a medical professional after any blows to the head.


TBI kills brain cells and can create chemical changes in the brain. It can also cause seizures, fluid build-up around the brain and nerve damage. These changes can lead to memory loss, communication problems, inability to properly move certain body parts, paralysis, permanent changes in behavior, coma and death, depending of the severity of the injury, according to the Mayo Clinic. 

No brain injury should be brushed off. Even mild TBI is serious. Around 75 to 90 percent of TBI-related deaths, hospitalizations and emergency department visits each year are concussions or other forms of mild TBI, according to the CDC.

Dr. Kory Gill, an assistant professor at the Texas A&M Health Science Center College of Medicine and team physician for Texas A&M University Athletics, told Live Science that the most important thing people should know about concussion is that they are not like other sports injuries where it is okay to "play hurt" or "play through the pain." 

"Playing when you have not completely recovered from a concussion is dangerous and could be deadly," said GIll. "Become familiar with the signs/symptoms of concussions, and if you think you or a teammate has a concussion speak up. It's actually a law (Zackery Lystedt Law) now that players/coaches/staff/parents be educated on concussions pre-participation."

Diagnosis & treatment

When a patient arrives for treatment the medical staff typically uses the Glasgow Coma Scale, a 15-point test, to determine the initial severity of a brain injury. The test is performed by checking a person's ability to follow directions and move their eyes and limbs. Clarity of speech is also tested. The higher the score, the less severe the injuries. CT scans and blood tests can be used to conclusively diagnose TBI. An intracranial pressure monitor is a probe that may also be inserted into the scull to measure pressure increases around the brain, according to the Mayo Clinic.

Rest is usually the most common treatment for mild TBI, though the patient should get back to normal activates as soon as the doctor allows. "While a short period of rest is important to allow the brain some time to heal, extended rest and sensory reduction (no TV or electronics) actually prolongs symptoms rather than helping," said Dr. Kenneth Podell, a neuropsychologist at Houston Methodist Hospital. When in doubt, consult with a medical professional.

Treatment for moderate to severe TBI varies. Maintaining blood pressure, keeping the patient's oxygen supply normal and preventing any additional injury is key. Surgery may be needed to repair the brain, remove any foreign objects or to relieve pressure on the brain.

Dr. Vani Rao, a neuropsychiatrist at Johns Hopkins University School of Medicine and co-author of "The Traumatized Brain: A Family Guide to Understanding Mood, Memory, and Behavior After Brain Injury" (Johns Hopkins Press, 2015), noted that the majority of people who sustain a single concussion recover without any long lasting consequences. However, multiple concussions can increase risk for developing chronic neuropsychiatric problems such as depression, aggression, cognitive problems.

Additional resources

Alina Bradford
Live Science Contributor
Alina Bradford is a contributing writer for Live Science. Over the past 16 years, Alina has covered everything from Ebola to androids while writing health, science and tech articles for major publications. She has multiple health, safety and lifesaving certifications from Oklahoma State University. Alina's goal in life is to try as many experiences as possible. To date, she has been a volunteer firefighter, a dispatcher, substitute teacher, artist, janitor, children's book author, pizza maker, event coordinator and much more.