What is a common physical symptom of a concussion?

Dizziness is a common physical symptom of a concussion due to the disruption that occurs in the brain following a head injury. When a concussion happens, it affects the brain's ability to process information and maintain balance, often resulting in feelings of lightheadedness or vertigo. This can lead to challenges in maintaining equilibrium while standing or walking, which are critical factors in daily functioning and physical activity.

The other options do not accurately reflect typical physical manifestations of a concussion. For example, increased appetite is not associated with concussions, as the body's response typically leads to a decrease in appetite due to nausea. Rapid heartbeat can occur in response to stress or anxiety rather than being a direct symptom of a concussion itself. Decreased sleep may result from various factors, including the anxiety or stress that can accompany head injuries, but it is not categorized as a primary physical symptom. Therefore, dizziness stands out as a key indicator, directly linked to the brain's compromised ability to coordinate and process information after trauma.