Loss of consciousness; however, loss of consciousness may not occur in some concussion cases
Dilated (the black center of the eye is large and does not get smaller in light)or unequal size of pupils
Vision changes (blurred vision or seeing double, not able to tolerate bright light, loss of eye movement, blindness)
Dizziness, balance problems
Respiratory failure (not breathing)
Coma (not alert and unable to respond to others) or semicomatose state
Paralysis, difficulty moving body parts, weakness, poor coordination
Slow pulse, and slow breathing rate, with an increase in blood pressure
Vomiting
Lethargy (sluggish, sleepy, gets tired easily)
Headache
Ringing in the ears, or changes in ability to hear
Difficulty with thinking skills (difficulty "thinking straight", memory problems, poor judgment, poor attention span, a slowed thought processing speed)
Inappropriate emotional responses (irritability, easily frustrated, inappropriate crying or laughing)
Difficulty speaking, slurred speech, difficulty swallowing
Body numbness or tingling