Concussions are graded as
- mild (grade 1)
- moderate (grade 2)
- severe (grade 3)
depending on such factors as loss of consciousness, amnesia, and loss of equilibrium.
- In a grade 1 concussion, symptoms last for less than 15 minutes. There is no loss of consciousness.
- With a grade 2 concussion, there is no loss of consciousness but symptoms last longer than 15 minutes.
- In a grade 3 concussion, the person loses consciousness, sometimes just for a few seconds.