Wow! Thanks all for so many responses. Yes, it DID hurt and it still does. I spoke to NHS Direct who told me it will almost certainly fall off and there's nothing I can do to stop it but that a new one will grow (as many of you have said, thanks). My worry was that my father lost a toe nail with a hammer and the nail never did grow back. I haven't seen a doc but now will, as so many think I should - and you're right, of course.

(I am using my second finger to type for those who wonder. This finger probably gets more use than the average person - whoever that is - because I am a lutenist.)