A concussion where the immediate symptoms only last for a few minutes can start to manifest new or more symptoms a day or more later. But, those immediate symptoms will always be present first. For most, these delayed symptoms do not manifest.

A person who has anxiety about head hits can become anxious with their anxiety building to a point of causing similar symptoms eve if the hit was not a concussive hit. Touching the contact spot and finding it to be tender can reinforce this anxiety. But, a scalp injury is not a concussion any more than smashing your thumb with a hammer is a broken arm.