but a traumatic bruise beneath the nail is often a minor injury and usually improves as the nail grows.
Why Does the Nail Become Dark?
The dark color usually comes from blood trapped beneath the nail plate.
Unlike a bruise on the skin, where the blood can spread into surrounding tissue, blood underneath a nail has limited room to move. It therefore remains concentrated beneath the nail and can appear dark purple, blue, or almost black.
As the nail grows, the discolored portion gradually moves toward the tip. Fingernails can
