what causes a toe to turn black
Non-Traumatic Injuries. There are several other causes of toenails turning black, which include systemic chronic health problems, chronic ingrown toenails, and fungal infections. There is also a rare more serious cause of black discoloration of a toenails resulting from cancer known as malignant melanoma.
Black toenails are caused by trauma to the nail. Common causes of toenails turning black include ill-fitting shoes, fungus, dropping an object on the toe and cutting the nail too short. Impact to the toenail causes bleeding underneath the nail's surface. Part or all of the toenail may turn black.