Concussion symptoms vary from person to person-just as people are all uniquely different, including the following:

Alteration of Consciousness:

The single defining symptom is that of “alteration of consciousness” resulting from a force to the head OR a force to the body that causes a “whiplash of the brain” .  The “alteration of consciousness” can vary from a “coma” (“out cold”) to “lethargy” (“brain fog”).

There are no hard-and-fast tests to confirm a concussion injury in most cases.  The diagnosis is usually made on the basis of the determination of clinical symptoms typical of a concussion injury.  But it is important to remember that the clinical presentation varies widely from patient to patient. There is no “classic” , defining case.

The single determining factor is that of an alteration of unconsciousness due to a force to the head or to another body part that causes a whiplash force to the brain. Often, the victim will not realize that they have sustained a concussion.  By definition, if a person has been unconscious, you can’t be expected to be conscious of the fact that he or she has been unconscious.  Likewise, a person who has suffered an alteration of mental function can’t be expected to be aware of the symptoms of a concussion.


Headache is the most common and most persistent symptom of a concussion injury, occurring in up to 90% of cases.

Several studies have reported that persistent post – traumatic headaches are more common after concussion injuries that after severe TBI.

Posttraumatic headache is associated with a high degree of disability.

Postconcussion headaches are generally of two different types. The first type resembles that of tension type headaches,  the second type was commonly resembles migraine headaches.

Research shows that persons with a prior history of headaches are at significantly greater risk for the development of postconcussion headaches.

Sleep-Wake Disturbances

Sleep disturbances have been reported in more than 50% of concussion cases. They include insomnia, hypersomnia, obstructive sleep apnea, for sleep maintenance, poor sleep efficiency, early awakening, delayed sleep onset, and or alterations in circadian cycle.

Cognitive Problems:

Concussion injuries often caused disruption in cognitive skills that include problems with attention/concentration, processing speed, learning/memory and executive function.

Memory deficits are often the most obvious of the cognitive problems from concussions.  The immediate loss of memory is defined as amnesia.  The inability to remember events immediately following the trauma is called Post Traumatic Amnesia (PTA). Concussion experts believe that the amount of post traumatic amnesia is a more important indicator of the severity of the brain injury than the loss of consciousness.

The inability to remember events immediately before the trauma is called Retrograde Amnesia.  Retrograde amnesia is the inability of a concussion victim to remember events immediately before the traumatic event. Retrograde amnesia is considered an indicator of more severe brain injury.

Word-finding difficulties and poor name recall are two types of memory impairments that are seen with concussion injuries.

Span of concentration is the ability to stay “on task”, to stay focused on the issues at hand.  Losing the though in the middle of a sentence or the middle of a conversation is a typical span of concentration problem.

Executive functioning involves the ability to plan and organize.  It involves the ability to “multi-task”, keeping track of multiple ideas simultaneously.  Difficulty with multi-tasking is a common cognitive impairment related to concussions.

Vestibular Dysfunction:

Vestibular dysfunction frequently occurs in connection with concussion.   The brain controls most bodily functions, including the vestibular system.  The vestibular system includes the inner ear and the brain that help to control balance and eye movements. Persistent vertigo, dizziness, imbalance and visual disturbance are common symptoms of patients with concussion injuries.  These problems involve a combination of brain injury and vestibular injury which are supposed to work together in harmony but do not in many concussion cases.


(For more information, click on the vision section.)

Vision Disorders:

Vision problems are very a very common symptom of concussion.  Concussions do not involve injury to the eyeball itself.  They involve injury to the brain and other body parts that affect vision.

Beause post-concussion vision problems come from the brain and not the eyeball, visual acuity (the ability to read an eye chart) is hardly ever a symptom of concussion.

The most common immediate vision-related concussion symptom is often that of blurred vision, i.e. “can you count how many fingers?”  It is often accompanied by dizziness and balance issues.

The second immediate symptom is light sensitivity, sometimes called “photophobia”.  The term photophobia is technically incorrect.  It is not a fear of light.  Rather it is insensitivity to light.

Instead, concussions cause problems with “vision in motion”, called oculo-motor dysfunction.  Concussion victims sometimes experience the following:

  • Difficulty changing focus from near to far and back.
  • Difficulty focusing on near objects (convergence insufficiency).  following a moving visual target.
  • Difficulty following a moving object.
  • Difficulty scanning the visual field.

Concussions can also cause a loss of visual field, usually in the peripheral visual field.

Vision problems caused by concussion can be very disabling, interfering with the ability to read printed material, use a computer, drive a car and many other activities of daily living.

Persistent Fatigue:

Fatigue is a major problem resulting from concussion injuries with nearly 30% of concussion victims experiencing fatigue problems.

Fatigue is a multidimensional problem with can affect physical, cognitive, motivational, and psychological (i. e. Depression, anxiety) spheres. Individuals with fatigue can experience poor problem-solving and coping skills which then create a vicious circle leading to increased stress and depression. Energy, or lack thereof, can be the difference between a “rock star” and a “dud”.  Without the motivation from energy, many human qualities can be wasted.

Fatigue is one of the most pervasive symptoms of a concussion injury. Studies show that nearly 30% of concussion victims experience persistent fatigue at three months post injury. One study reported a level of fatigue in concussion victims comparable to that of multiple sclerosis patients

Mental Health Problems:

Mental health disorders are common following concussion injuries. This includes mood disorders with symptoms of depression and anxiety.

Post Traumatic Stress Disorder (PTSD) occurs quite often at the same time as concussion.

Depression is a common side effect of concussion.

Anxiety is very common.  Many victims of car accidents have difficulty with either driving a motor vehicle or riding as a passenger.  Often concussion victims have more anxiety while riding as a passenger than they do when driving for the simple reason that passengers have no control over the operation of the vehicle.

In addition to the immediate symptoms of confusion and agitation, concussions have been associated with the late development of psychiatric disorders, such as obsessive compulsive disorders, anxiety disorders, psychotic disorders, mood disorders and depression.

Irritability/Personality Change:

Concussion injuries have been shown to magnify many of the many of the personality “quirks” that we all deal with daily. Some of us are introverts and some extroverts.  Some people are highly organized and others disorganized.  Some are exuberant.  Others more dismal.

People with those inherent personality traits are at high risk from the aggravation of those “trait”  by a concussion injury.  The slightly “scatterbrained” becomes seriously disorganized with a loss of executive function which prevents that person to move forward in life.  The slightly introvert becomes a complete reluse