Concussions are graded as

  1. mild (grade 1)
  2. moderate (grade 2)
  3. severe (grade 3)

depending on such factors as loss of consciousness, amnesia, and loss of equilibrium.

  1. In a grade 1 concussion, symptoms last for less than 15 minutes. There is no loss of consciousness.
  2. With a grade 2 concussion, there is no loss of consciousness but symptoms last longer than 15 minutes.
  3. In a grade 3 concussion, the person loses consciousness, sometimes just for a few seconds.