Black toenails are generally found in long distance runners. Rubbing the toes against the toe box of your running shoe for long periods of time will cause a blood blister under your toe nail. They can also be found in runners that do a lot of downhill running. As you go down hills, your toes will thrust into the front of your shoes.
You can do your part to help prevent black toenails. First of all, make sure that you are wearing running shoes that fit you correctly. The best thing is to be fitted at a qualified running store. A general rule of thumb is that your running shoes should be ½ size larger than your regular street shoes. In addition to the rubbing of your toes into your shoe’s toe box, your feet will expand as you run long distances. A shoe fitted properly will keep you running comfortably.
Another way to help prevent black toenails is to make sure that your toenails are always trimmed. I also recommend going for a pedicure every 3-4 weeks to make sure that your feet and toenails are properly taken care of. I do this myself, and I’ve heard from many runners how they have avoided black toenails altogether since they started getting regular pedicures.
Black toenails are uncomfortable, but not usually so much that you cannot run. Eventually, it will run its course and the toenail will fall off. If you do find that the pressure is too much for you, there is a home remedy that you can do. However, you need to be cautious doing this. Sterilize your toenail with alcohol and a pin with a lit match. While the pin is still hot, you can gently press it into the center of your toenail to drain it. It really sounds worse than it is – and you will be immediately better. But, I would only recommend doing this if the pain is simply unbearable.
Black toenails are common – and usually just a nuisance. However, if you find that it isn’t getting better after a time – or it becomes red, please see a doctor about it.