What Can Cause A Black Toenail?

Changes In Skin Pigmentation Over Time

There are a variety of conditions that can cause changes in skin pigmentation over time. If patches of an individual's skin become darker than others, this can affect the color of their toenails. When this is the case, they'll typically notice darker patches of skin in areas surrounding the toenails or on other portions of the body. Injury, inflammation, and illness can all lead to differences in skin pigmentation. It's also possible for discolored patches of skin to develop because there are varied melanin levels throughout the body. Melanin is responsible for coloring the skin and offers protection from the sun. If the skin overproduces melanin in certain areas, it can lead to spots or patches of discoloration.