Anxiety can cause a cascade of symptoms that can last for days or longer. Anxiety feeds anxiety. The startle response from the bump can set off a whole range of chemical reactions that need to settle down and balance out.

Startle response is like the 'fight or flight' response. It is chemical, not physically traumatic. If you feed the startle response with 'Did this bump cause brain damage?' the effects and anxiety can last a long time. Some take weeks to get over a startle response because they are convinced there was damage caused. Only when they get distracted with other things in their life and forget about the event do they let go of the anxiety and get back to normal.

NO, this was not brain damage.