Recently, I noticed some discolouration on my big toe. The nail seems to be blackened near the bottom of the nail bed on the right side. That bothers me as it is, but I've noticed a lot of numbness in the toe as well. This toe has always caused me problems...a few years ago it was broken when a horse stepped on it, and it never healed properly. I still have full mobility and there is no pain (except when I try to bend it, but this is normal, see the injury). Should I be worried?