Quick Answer
A concussion occurs when your brain is jarred inside your skull - usually from a direct blow to the head, face, or neck, or from a forceful impact to the body. This sudden movement can temporarily disrupt how your brain functions, leading to symptoms such as headache, confusion, dizziness, and memory problems.
Understanding the Mechanics
When a concussion occurs, the brain experiences sudden movement that temporarily disrupts how nerve cells communicate and how the brain manages energy. While the brain usually recovers fully, these changes explain why symptoms occur. Key effects include:
- Temporary brain cell disruption: Nerve cells may not fire or communicate normally, affecting thinking, memory, and coordination.
- Chemical imbalances: Shifts in important brain chemicals can contribute to headaches, dizziness, or sensitivity to light and noise.
- Increased energy demands: The brain works harder to restore balance, which can lead to fatigue, "brain fog," and slower thinking.
- Blood flow changes: Concussion can temporarily alter blood flow, affecting how well different areas of the brain function.
- Subtle structural effects: Even if standard CT or MRI scans look normal, tiny changes in brain connections and pathways may occur, contributing to lingering symptoms.
- Inflammatory response: The brain may trigger mild inflammation, which can affect recovery and contribute to ongoing symptoms.
It's Not About "Blacking Out"
A common misconception is that you must lose consciousness to have a concussion. In reality, most concussions happen without any loss of consciousness. You can sustain a concussion while remaining fully awake and aware.
Common Causes
Concussions can happen in many situations:
- Sports activities - Contact sports like football, hockey, soccer, and basketball
- Motor vehicle accidents - Car crashes, even at low speeds
- Falls - Slipping on ice, falling from a ladder, or playground accidents
- Physical assault - Any direct blow to the head or body
- Blast injuries - Military personnel may experience concussions from explosions
What Makes It Serious?
While often called a "mild" brain injury, concussions should always be taken seriously. The temporary disruption in brain function can:
- Affect your ability to think clearly and process information
- Impact memory, concentration, and decision-making
- Cause physical symptoms that interfere with daily activities
- Increase vulnerability to further injury if not properly healed