Signs and symptoms of concussion and mild traumatic brain injury

Symptoms may appear up to 48 hours after an incident that may have caused a mild traumatic brain injury (mTBI) or concussion. Symptoms can vary from one person to another, even in situations where the context and the injury are similar.

Symptoms commonly observed or experienced after an mTBI/concussion may be physical, cognitive or emotional.

Physical symptoms that may be observed or experienced after an mTBI/concussion include:

• Headaches
• Dizziness, vertigo
• Blurred vision
• Sensitivity to light or noise
• Nausea
• Fatigue, sleep difficulties (e.g., difficulty falling asleep)

Cognitive symptoms that may be observed or experienced after an mTBI/concussion include:

• Feeling slowed down
• Difficulty maintaining concentration or attention
• Difficulty understanding or remembering information

Emotional symptoms that may be observed or experienced after an mTBI/concussion include:

• Feeling unusually emotional (e.g., more anxiety, irritability or sadness)
• Symptoms of depression

This list is not exhaustive and other symptoms may be observed or experienced.

If there are symptoms, consult the page What to do following an incident involving an impact or impulsive force to the body or head.

Some symptoms are classified as warning signs and require an immediate evaluation at the emergency department or by calling 911.

Physical warning signs are:

• Severe or worsening headache
• Repeated vomiting
• Double vision or loss of vision
• Convulsions (uncontrollable and repetitive body movements)
• Difficulty walking or speaking
• Weakness or loss of sensation in an arm or leg

Cognitive warning signs are:

• Deterioration of consciousness
  • Difficulty staying away (significant drowsiness)
  • Confusion
  • Loss of consciousness
• Difficulty recognizing people or places

Emotional warning signs are:

• Increasingly agitated or aggressive behaviour
• Excessive crying
• Unusual behaviour

The signs and symptoms presented on this page are taken from the Institut national d'excellence en santé et en services sociaux' information leaflet intended for the general public. It should be noted that certain signs and symptoms may be more specific to certain individuals, particularly school-aged children or people involved in sports and leisure activities. For more specific information tailored to these individuals, consult the tools developed by the ministère de l’Éducation.