A nail fold overlies the distal phalanx of every toe and is the structure that supports the growth of a toenail. The white semicircular structure at the base of every toenail is called the lunula.


Subungual hematoma is a blood collection under the toenail resulting from trauma or repetitive pressure and may be painful.

Malignant melanoma has a predilection for the nail fold and may be identified as darkly discolored skin underneath the toenail.

Chronic fungal infections may cause toenail thickening, deformity, and discoloration

Paronychia is an infection of the nail fold surrounding the edges of the toenail and is often associated with ingrown nails.