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 ...

A small black line that forms vertically underneath your nail may be a splinter hemorrhage, while horizontal lines may be melanonychia. These may be harmless or a sign of a more serious health ...

A black line in the nail may be simply a color variation, but it can also result from an injury. Other possible causes include the use of certain drugs and various health conditions, including HIV and ...

Clean and beautiful nails enhance the beauty of hands. But if the nails start to deteriorate, break, turn black, or turn yellow, or if lines start appearing on the nails, then this is not a normal ...