(HealthDay News) -- A concussion is a brain injury caused by a violent blow to the head.
The American Association of Neurological Surgeons says common warning signs of concussion include:
- Persistent headache.
- Vision problems.
- Dizziness, nausea or vomiting.
- Impaired balance, confusion, trouble concentrating or memory loss.
- Ringing in the ears.
- Sensitivity to light.
- Diminished senses of taste or smell.