About concussion


What is Concussion?

Concussions are injuries that happen when you hit your head (or something else hits it) or if you experience jolting or shaking of the head (like in whiplash).  You don’t need to have an impact directly to your head or lose consciousness to experience a concussion.

Concussions might involve injury to your brain, but they can also cause injuries to other parts of the head and neck.  Symptoms after concussion can be a result of any of these factors or because of things that develop as a result of the injury.


What are the signs?

Everyone’s experience after having a concussion is different.  In general symptoms might include the following:

Key Points

  • You don’t need to lose consciousness or have amnesia to have a concussion, and it won’t show up on a CT or MRI scan.  Symptoms also don’t need to be immediate and might also develop over a few days.
  • Concussion symptoms are normally temporary and get better over time.
  • In most cases they resolve in a few days or weeks.  If symptoms start getting worse, or if you experience any Red Flags, seek out medical help right away.
Red Flags include: Fainting, falling or blacking out, drowsiness, can’t be woken up, constant severe headache, repeated vomiting, ongoing amnesia, increased confusion,  significant change in behaviour,  paralysis, weakness in arms or legs, double vision, worsening of vision, slurred speech.


What causes symptoms?

Concussions can cause microscopic injury to your brain and brain cells.  Each injury is different, but in general symptoms can be caused by any of the following:

  1. Brain stretches and changes shape - causing injury to the tissues and cells
  2. Brain cells don’t work as well temporarily
  3. Changes in the connectivity and activation of brain areas
  4. Changes in blood flow and the amount of energy and oxygen in the brain
  5. Changes in how the brain makes and uses energy
  6. Inflammatory changes (not the same thing as swelling)


Injury to your neck, vestibular system or other nerves that can cause symptoms that look a lot like concussion.


When am I most at risk?

After getting a concussion, your brain might be vulnerable to additional injury for two weeks or more.  It’s very important to avoid any activities that have a risk of concussion for at least a few weeks, sometimes longer.

There is no test that can say you are 100% clear and safe to return to high risk activities, so we rely on clinical judgement.  It's best to be safe and restrict any risky activity for at least a few weeks even if you are symptom free, and perform well on clinical tests.


What is cte and Will I get it?

Chronic traumatic encephalopathy (CTE) is a degenerative brain disease that few people develop after a long history of repetitive brain trauma.  It is rare, mostly found in people who experience hundreds or thousands of hits to the head and has not been linked to concussion.  Getting a concussion does not put you at risk for developing CTE.