Why is it easier to get a concussion when you have already had one? is this always the case?

Gets worse.: It certainly seems reasonable that a second concussion is more likely to occur after having one already. It takes longer to recover from a second concussion after already having one. Of course, it is hard to say it is always the case, but it is pretty much the prevailing theory.

Clarification: Not so sure that it is easier to have additional concussions, but very clear that subsequent concussions can cause more problems and lengthier recovery periods. However, be aware that bumping your head is not necessarily a concussion unless loss of consciousness, amnesia, or combination of both.

RECOVERY: No two concussions are alike nor is recovery. Evidence does suggest that more concussion events are cumulatively 'worse'. A more accurate statement would be that it may be easier to sustain another concussion if one returns to participation in a concussion-prone activity prior to being deemed fully recovered. Recovery should be monitored and determined by a skilled clinician.