Inspired by this thread.
I lost a thumbnail as a kid and a toenail as an adult. Both instances were preceded by a hard impact: I had smashed my thumb between two rocks, and I had stubbed my toe very hard into a wall. These impacts were not enough to break bones, but in both cases, the victim-digit’s nail fell off a week or two later.
So why does the nail come off?
Swelling detaches the under-connection of the bed to the nail in some cases, but fluid buildup from the injured bed is the more significant cause. Sometimes, a sports doctor who can act quickly enough (I’d guess within the hour of the injury) will drill a small drain hole in a damaged nail to relieve the pressure, and with bandaging that’s enough to let the nail heal back into place before it completely detaches. For most of us, by the time we realize we really did whack our toe that hard, it’s too late.
Just a name/subject applause post.