A concussion may result in a variety of symptoms, which can be loosely placed in four categories: physical, cognitive, emotional, and sleep-related.  A patient may likely experience symptoms across more than one category. Even if a patient has sustained previous concussions, they may experience a completely different set of symptoms with a new injury.

An athlete who demonstrates any of the following signs or symptoms following a direct or indirect blow to the head, should be removed from play and should not return to play until evaluated by a healthcare professional.

Physical symptoms include headache, dizziness, balance problems, nausea, vomiting, sensitivity to light or noise, numbness & tingling, and fatigue.

Cognitive symptoms include feeling mentally foggy, feeling slowed down, confusion, difficulty concentrating, and difficulty remembering events before or after the injury.

Emotional symptoms consist of irritability, sadness, feeling more emotional than usual, and nervousness.

Sleep-related symptoms are drowsiness, sleeping more or less than usual, and trouble falling asleep.