I have an odd, but not particularly bothersome, condition on both of my pinky toes. For as long as I can remember (at least since early childhood) the toenails on said toes have been split. That is to say, there is the main nail, and then a thin little sliver of nail that grows independantly, on the “outer” side of the toe. While the sliver grows along with the main nail, and even sometimes seems to cleave to it, it’s obvious that they’re not all one piece, and usually stress or being soaked in water leads to the small piece loosening and breaking off at some point. And then the sliver grows back again.
My question is: what causes this? Am I the only person this happens to, and is there any procedure I can follow to have whole pinky toenails again? I always assumed that if I left them alone, eventually the nails would grow properly, but as I’m now in my mid-20s, my faith in that assumption is sort of shaken.
Granted, this is a rather minor concern; it has never actually caused me any problems. It’s just…odd and I wonder if any of the Teeming Millions know what’s going on. Thanks!
–Amy
If you want to get rid of it, a doctor can kill the cells that grow nails. You could probably get just the sliver nail killed.
Carpe hoc!
As with all personal medical problems, the best advice is always “see your doctor.”
Nickrz
For The Straight Dope
Actually, you might have a vestigial remnant of a vestigal toe. 
Queen Elizabeth’s mother, Anne Boleyn, was said to have an extra finger - one excuse for accusing her of witchcraft - but really it was only a tiny vestigal fingernail on the outside of her pinky.
You lucky thing, you.
“Knowing others is wisdom. Knowing yourself is enlightenment.” - Lao-tzu, Chinese philosopher
It happens to me too, sometimes. I never gave it much thought, I just assumed it was because the little nail gets stressed from shoes and breaks off. I just clip 'em.
Happened to me too, for a long while. It’s stopped now - though I couldn’t actually back this up, I figured it had to do with my diet (not enough proteins for nail strength) and the shoes I was wearing. I just clipped 'em off as they got too long and caught on my socks.
Try eating more Jell-O and see what that does for you.
Cave Diem! Carpe Canem!
There was probably a small split between the cells of the nail bed sometime during your development. You can have it fixed or leave it alone.