Black Toenails
A black, purple, discoloration under or involving a toenail is frequently due to trauma to the toe nail, such as when something is dropped on the toe or toe hitting the end of the shoe. The color results from a blood clot or bleeding under the nail, and may involve the entire nail or just a small portion of it. Sometimes, the bruise can lead to a fungal nail infection. In rare instances black toenails can be as a result of malignant melanoma.