I think we all get them from time to time.
Touch wood (I almost wrote food then lol), I've got none at the minute but I do have a little piggy nail that's just about done growing back.
IMO poorly fitting shoes are to blame - when the shoe's slightly too restrictive in the forefoot and your toenails constantly pound the front of the shoe and so end up bruised.
Unless you've damaged the nail bed, it'll more than likely grow back normal and pain-free. As a safeguard, I generally smear some Germolene around it to keep infections at bay though - after I had a toe infection a few months ago, I can tell you I wouldn't want a repeat of that experience!
Edited: 16/07/2010 at 17:25