Although the causes are entirely physical, Traumatic Brain Injury (TBI) is unlike almost any other physical injury. While a broken arm or a punctured lung may affect one’s ability to control their body or limit what they can do in life, TBI also causes personality and cognitive changes that, in most cases, do not regain their previous levels of function.

The brain is a complex organ. As a result, no two brain injuries are exactly alike. Instead of being considered a single condition, TBI ranges from mild to severe depending on what symptoms emerge.

The impact of these injuries are measured in: severity of the physical injury, rate and completeness of physical recovery, available resources for recovery, affected functions, the impact of losing functions on a patient’s daily life and which areas of the brain are not affected by the injury.
Moderate to severe TBI can have a large number and variety of symptoms. The following table lists these symptoms by type:


  • Difficulty paying attention or concentrating
  • Becoming easily distracted
  • Trouble remembering things
  • Reduced mental processing speed
  • Becoming easily confused
  • Repetition of a particular response, such as a word, phrase or gesture (Perseveration)

Speech and Language 

  • Inability to understand speech (Receptive aphasia)
  • Difficulty speaking and being understood (Expressive aphasia)
  • Slurred speech
  • Speaking too fast or slow
  • Difficulty reading or writing


  • Difficulties interpreting touch, including temperature, movement, limb position and fine motor skills
  • Difficulty recognizing patterns
  • Partial to total loss of vision, including weakness of eye muscles and double vision (Diplopia)
  • Blurred vision
  • Problems with depth perception
  • Involuntary eye movement (Nystagmus)
  • Sensitivity to light (Photophobia)
  • Decreased or complete loss of hearing
  • Ringing in the ears (Tinnitus)
  • Sensitivity to sounds
  • Loss or diminished sense of smell
  • Loss or diminished sense of taste

Physical Changes 

  • Seizures
  • Paralysis or spasticity
  • Chronic pain
  • Loss of control over bowels or bladder
  • Sleep disorders, such as insomnia
  • Loss of stamina
  • Change in appetite
  • Changes in body temperature
  • Menstrual difficulties

Social and Emotional 

  • Behaviors of dependency
  • Inability to control emotions
  • Lack of motivation
  • Irritability, aggression and anger
  • Depression
  • Loss of control over impulses
  • Denial and lack of awareness

The FOCUS Marines Foundation (FMF) is partnered with a variety of organizations that can provide resources for those suffering from the physical and cognitive challenges caused by TBI. Our FOCUS program also offers our participants the tools they need to manage the social and emotional challenges they will face. The FMF is here to provide support and community for any who need it.