Why is my toenail black? Blood under a nail is the usual cause. This is most often seen in runners, hikers, or people who wear steel toe shoes often. Reddish, purplish, brownish nails can result from a fungus growing between the nail and the skin under the nail. If the color change has been more gradual this is the most likely cause.
An injury to a toe, repetitive traumatic athletic action, and ill-fitting shoes can also all cause toenails to turn black. Melanoma (skin cancer) under the toenail can cause the nail to be black as well. This is rare but obviously very serious. In my practice I have seen one patient who did not go to the doctor for several years after noticing this growth and dark color change under his big toenail. He ended up losing his life due to the fact he waited too long. By the time he was diagnosed, the cancer had already spread and metastasized. If you notice dark discoloration under the nail, don’t wait, get in to see one of our experts at IPG.