I had three small concussions in one day. Symtoms lasted for about 2 weeks. After that I felt fine.

Three months later I got a viral infection. I got not only the regular symtoms from an infection, but my concussion symtoms came back at full force. After the infection had cleared so did my concussion symtoms.

This led me to understand that my head wasnt fully healed even if it felt like it.


Im not sure I understood your question correctly but anyhow, infections/cold etc reveals the weak spots on your body for sure.