What Is a Traumatic Brain Injury (TBI)? | Shapiro, Washburn & Sharp

The numbers are a little out of date, but these two sentences from the Centers for Disease & Prevention’s traumatic brain injury and concussions facts page drive home the seriousness of TBIs:

From 2006 to 2014, the number of TBI-related emergency department visits, hospitalizations, and deaths increased by 53 percent. In 2014, an average of 155 people in the United States died each day from injuries that include a TBI.


The three leading causes of TBIs are falls, motor vehicle crashes and being struck by objects such as items dropping from overhead or weapons wielded in assaults. Regardless of why a traumatic brain injury occurs, the symptoms can be severe and disabling—sometimes for life.

According to diagnostic criteria endorsed by the National Institutes of Health, mild TBIs produce

  • Headaches
  • Confusion
  • Lightheadedness
  • Dizziness
  • Blurred vision
  • Ringing in the ears
  • Tiredness or sleepiness
  • A bad taste in the mouth
  • A change in sleep habits
  • Behavior or mood changes
  • Trouble with memory, concentration, attention, or thinking
  • Loss of consciousness lasting a few seconds to minutes1
  • Sensitivity to light or sound
  • Nausea or vomiting

The “mild” designation indicates that the TBI victim will likely stop experiencing debilitating symptoms within days or weeks. Also, everyone who suffers a TBI will experience a different mix of symptoms.

Moderate or severe traumatic brain injuries leave people suffering from some combination of the following symptoms:

  • Loss of consciousness lasting a few minutes to hours
  • Enlargement of the pupil (dark center) of one or both eyes
  • Headaches that gets worse or won’t go away
  • Repeated vomiting or nausea
  • Slurred speech
  • Convulsions or seizures
  • An inability to wake up from sleep
  • Numbness or tingling of arms or legs
  • Loss of coordination
  • Increased confusion, restlessness or agitation

A TBI can occur even when a person remains conscious and does not suffer a skull fracture or structural damage to the brain itself. The most-severe brain injuries may induce paralysis and permanent cognitive disabilities. A TBI victim may require assistance with the most basic activities of daily living such as dressing, bathing and eating.

Any serious blow to the head can cause a TBI. So can having one’s head snap forward suddenly and with great force, as happens in most car and truck accidents. The injury results from the brain slamming into the inside of the skull, which also means that while a bicycle or motorcycle helmet protects against skull fractures, no helmet provides guaranteed protection against TBIs.

Seeking medical care after any type of accident that could cause a traumatic brain injury is essential. Diagnosing the problem and initiating treatment as soon as possible helps ensure the best outcome. Another reason to go to the doctor or visit an emergency room is that symptoms of TBIs do not always manifest immediately.