What is the term for a nail growing into the skin?

An ingrown toenail refers to a condition where the edge or corner of a nail grows into the skin, often leading to pain, swelling, and potential infection. This condition commonly affects the big toe but can occur with other toenails as well.

This term distinguishes the issue clearly from other conditions related to nails. A hangnail refers to a small piece of skin that has separated from the nail, and while it can be painful, it does not involve the nail growing into the skin. A nail bed infection pertains to an infection in the area beneath the nail, which is a different ailment and does not necessarily involve the nail itself growing improperly. Nail erosion involves the wearing away of the nail structure rather than the nail growing into the skin. Hence, "ingrown toenail" is the correct term to describe the phenomenon of a nail growing into the skin.