What Is a Concussion?

A concussion is a type of traumatic brain injury (TBI) that occurs when a blow to the head, neck, or body causes the brain to move rapidly back and forth inside the skull. This sudden movement can disrupt normal brain activity by stretching and damaging brain cells, even if there is no visible injury on the outside. Because concussions affect how the brain functions rather than its structure, they often go undetected on standard imaging tests like X-rays or CT scans.

Contrary to popular belief, losing consciousness is not required for a concussion to occur. In fact, most concussions happen without a knockout. Symptoms may appear immediately after the injury or gradually develop over the following hours or days, which can make recognition more difficult. Athletes, parents, and coaches should be aware that even minor impacts can result in a concussion if symptoms are present.

Common symptoms include:

• Headache or pressure in the head

• Dizziness or balance problems

• Confusion or difficulty concentrating

• Sensitivity to light or noise

• Nausea or fatigue

• Mood changes such as irritability, anxiety, or sadness

Concussions are most commonly associated with sports, especially contact sports like soccer, football, hockey, and basketball, but they can also occur during falls, car accidents, or everyday activities. Understanding what a concussion is helps promote early recognition, proper treatment, and safer participation in physical activity.