From trauma to a toenail fungus, there are many reasons why you may have a black toenail. Here's what it means, how to treat ...

Melanonychia occurs when you have brown or black lines in your nails. Learn about melanonychia, ... Melanocytic hyperplasia: This is an increase in pigment cells in your nail bed.

Melanonychia, also known as a dark or black line on the nail, causes a streak of dark pigmentation that runs along the nail bed.It can be a normal color variation, especially in people with darker ...

A narrow, vertical black line on your nail is called a splinter hemorrhage. Lines that create a horizontal stripe are called Beau's lines.

In mild cases, the black toenail will grow out naturally over time without treatment. In severe cases, such as when the nail begins to detach from the nail bed, a person should seek medical treatment.

Karolina Jasko said she had noticed a thin black line, also on her thumbnail. She went to the doctor for an unrelated infection, and a biopsy was ordered. Her entire nail bed was removed.