I bruised my big toe nail playing netball 4 days ago. the nail has discoloured (light blue-ish). swelling to matrix. moderate pain. will it fall off?

If the nail: plate (growth line) of the nail was not involved the nail will survive.. it will take a while for the discoloration to grow out, Hope this is helpful Dr Z

Probably not: The bluish color is probably blood from under the nail....this should resolve in time...In my experience, when a nail turns black, it is more likely to fall off...Dr. Murray Wellner