A black line on your nail (medically known as melanonychia) causes a streak of dark pigmentation that runs along the nail bed. It can be a normal color variation, especially in people with darker skin ...

Another woman was diagnosed with melanoma after noticing black lines under her thumb nail during a manicure. In the comments, many people urged her to seek help after seeing the black lines, telling ...

Melanonychia is a brown or black stain in your fingernail or toenail. You can have a dark line on one nail, a few nails, or all of your nails. The line is caused by the natural color in your body ...

A woman who shared what she thought was a mildly interesting photo of her thumb and toe online was urged by strangers to see a doctor after commenters warned the image could show signs of a serious ...