Around age 13 I was playing football with some friends in the snow. Guy I was chasing slipped and his foot flew back and kicked me in the shin. It hurt of course and I fell and minorly sprained my knee in the fall. No biggie though…I kept playing. When I got home I wrapped my knee with an Ace bandage and didn’t give it much more thought.
As it happened this was around Christmas and my whole family was home. All of them, except me, were suffering from a cold or flu (I forget). Apparently the bug was in me too but I had no symptoms.
What happened instead is the cold (or flu) decided to collect at the site of my shin injury (really nothing more than a minor bruise). Several days later I noted to my mom that my shin was slightly (barely) discolored and she decided to take me to our doctor. He didn’t know much about it so sent me across the street to see a specialist. Specialist met me in the ER (not because it was an emergency, just where we were told to wait) and in 30 seconds told my mom I needed to be admitted immediately.
Mind you I felt fine. I was in no pain at all.
As it happened my leg caught a cold (called osteomyelitis) and is quite serious.
Eventually, after many tests and days in the hospital, they treated it with drugs. Now it seemed it was super concentrated cold/flu bug and when it got out I got sicker than I have ever been from a cold. That lasted a couple days then I was fine.