From trauma to a toenail fungus, there are many reasons why you may have a black toenail. Here's what it means, how to treat it, and when you should call your doctor.

Let’s start with this, Runner’s Toe, aka black toenails from running, is not required to be in the club and is not a 100% certainty for all runners. We often treat our injuries like war stories.

Take, for example, “soap nails,” translucent “fruit water” manis, and iridescent “aurora nails.” After seeing EmRata bring black into the mix, I’m thinking it deserves a spot in the ...