GENERAL HISTOLOGY

Detailed explanation-1: -A severe injury could cause your nail to fall off. Once your nail matrix heals, your nail will usually start to grow again. It may take several weeks before you see your new nail appear. In cases of severe nail matrix damage, some or all of your nail may not grow back.

Detailed explanation-2: -If blood gathers under the nail or if you have bleeding around the nail, you have nail bed damage. If the nail cracks and falls off, your nail bed has been injured. If the nail is torn from your nail bed, there is no doubt that your nail bed has been damaged by the experience.